/
usr
/
share
/
doc
/
python3-docs
/
html
/
library
/
/usr/share/doc/python3-docs/html/library
mkdir
upload
Name
Size
Mode
Actions
2to3.html
61709
0644
edit
dl
rm
abc.html
41394
0644
edit
dl
rm
aifc.html
28114
0644
edit
dl
rm
allos.html
32236
0644
edit
dl
rm
archiving.html
11992
0644
edit
dl
rm
argparse.html
274984
0644
edit
dl
rm
array.html
33547
0644
edit
dl
rm
ast.html
39595
0644
edit
dl
rm
asynchat.html
32546
0644
edit
dl
rm
asyncio-dev.html
51869
0644
edit
dl
rm
asyncio-eventloop.html
111215
0644
edit
dl
rm
asyncio-eventloops.html
33026
0644
edit
dl
rm
asyncio-protocol.html
87431
0644
edit
dl
rm
asyncio-queue.html
23957
0644
edit
dl
rm
asyncio-stream.html
61005
0644
edit
dl
rm
asyncio-subprocess.html
58015
0644
edit
dl
rm
asyncio-sync.html
35678
0644
edit
dl
rm
asyncio-task.html
83968
0644
edit
dl
rm
asyncio.html
28026
0644
edit
dl
rm
asyncore.html
42706
0644
edit
dl
rm
atexit.html
18433
0644
edit
dl
rm
audioop.html
35442
0644
edit
dl
rm
base64.html
36454
0644
edit
dl
rm
bdb.html
43423
0644
edit
dl
rm
binary.html
12723
0644
edit
dl
rm
binascii.html
24745
0644
edit
dl
rm
binhex.html
11669
0644
edit
dl
rm
bisect.html
25602
0644
edit
dl
rm
builtins.html
11604
0644
edit
dl
rm
bz2.html
33358
0644
edit
dl
rm
calendar.html
39539
0644
edit
dl
rm
cgi.html
55881
0644
edit
dl
rm
cgitb.html
12765
0644
edit
dl
rm
chunk.html
16872
0644
edit
dl
rm
cmath.html
34171
0644
edit
dl
rm
cmd.html
43811
0644
edit
dl
rm
code.html
27886
0644
edit
dl
rm
codecs.html
134071
0644
edit
dl
rm
codeop.html
14304
0644
edit
dl
rm
collections.abc.html
60912
0644
edit
dl
rm
collections.html
154946
0644
edit
dl
rm
colorsys.html
12627
0644
edit
dl
rm
compileall.html
28263
0644
edit
dl
rm
concurrency.html
21203
0644
edit
dl
rm
concurrent.futures.html
60660
0644
edit
dl
rm
concurrent.html
7959
0644
edit
dl
rm
configparser.html
141052
0644
edit
dl
rm
constants.html
17500
0644
edit
dl
rm
contextlib.html
88801
0644
edit
dl
rm
copy.html
13841
0644
edit
dl
rm
copyreg.html
14725
0644
edit
dl
rm
crypt.html
20331
0644
edit
dl
rm
crypto.html
10914
0644
edit
dl
rm
csv.html
69043
0644
edit
dl
rm
ctypes.html
264529
0644
edit
dl
rm
curses.ascii.html
25197
0644
edit
dl
rm
curses.html
175551
0644
edit
dl
rm
curses.panel.html
16706
0644
edit
dl
rm
custominterp.html
8734
0644
edit
dl
rm
datatypes.html
23950
0644
edit
dl
rm
datetime.html
306435
0644
edit
dl
rm
dbm.html
43119
0644
edit
dl
rm
debug.html
13983
0644
edit
dl
rm
decimal.html
233486
0644
edit
dl
rm
development.html
25123
0644
edit
dl
rm
difflib.html
96156
0644
edit
dl
rm
dis.html
106191
0644
edit
dl
rm
distribution.html
10506
0644
edit
dl
rm
distutils.html
10884
0644
edit
dl
rm
doctest.html
179752
0644
edit
dl
rm
dummy_threading.html
9316
0644
edit
dl
rm
email.charset.html
26431
0644
edit
dl
rm
email.compat32-message.html
86150
0644
edit
dl
rm
email.contentmanager.html
30028
0644
edit
dl
rm
email.encoders.html
14250
0644
edit
dl
rm
email.errors.html
19704
0644
edit
dl
rm
email.examples.html
57872
0644
edit
dl
rm
email.generator.html
41798
0644
edit
dl
rm
email.header.html
31219
0644
edit
dl
rm
email.headerregistry.html
57670
0644
edit
dl
rm
email.html
27741
0644
edit
dl
rm
email.iterators.html
13532
0644
edit
dl
rm
email.message.html
87210
0644
edit
dl
rm
email.mime.html
36081
0644
edit
dl
rm
email.parser.html
47430
0644
edit
dl
rm
email.policy.html
75241
0644
edit
dl
rm
email.util.html
33853
0644
edit
dl
rm
ensurepip.html
18700
0644
edit
dl
rm
enum.html
133949
0644
edit
dl
rm
errno.html
41331
0644
edit
dl
rm
exceptions.html
85151
0644
edit
dl
rm
faulthandler.html
23396
0644
edit
dl
rm
fcntl.html
27321
0644
edit
dl
rm
filecmp.html
25036
0644
edit
dl
rm
fileformats.html
11129
0644
edit
dl
rm
fileinput.html
30030
0644
edit
dl
rm
filesys.html
13418
0644
edit
dl
rm
fnmatch.html
16987
0644
edit
dl
rm
formatter.html
37666
0644
edit
dl
rm
fpectl.html
17538
0644
edit
dl
rm
fractions.html
29918
0644
edit
dl
rm
frameworks.html
13471
0644
edit
dl
rm
ftplib.html
54429
0644
edit
dl
rm
functional.html
9002
0644
edit
dl
rm
functions.html
201486
0644
edit
dl
rm
functools.html
64951
0644
edit
dl
rm
gc.html
29524
0644
edit
dl
rm
getopt.html
25353
0644
edit
dl
rm
getpass.html
12061
0644
edit
dl
rm
gettext.html
76641
0644
edit
dl
rm
glob.html
18432
0644
edit
dl
rm
grp.html
12383
0644
edit
dl
rm
gzip.html
32669
0644
edit
dl
rm
hashlib.html
79554
0644
edit
dl
rm
heapq.html
35529
0644
edit
dl
rm
hmac.html
17827
0644
edit
dl
rm
html.entities.html
11361
0644
edit
dl
rm
html.html
11108
0644
edit
dl
rm
html.parser.html
41842
0644
edit
dl
rm
http.client.html
65250
0644
edit
dl
rm
http.cookiejar.html
96195
0644
edit
dl
rm
http.cookies.html
39329
0644
edit
dl
rm
http.html
37602
0644
edit
dl
rm
http.server.html
58191
0644
edit
dl
rm
i18n.html
10464
0644
edit
dl
rm
idle.html
48412
0644
edit
dl
rm
imaplib.html
67339
0644
edit
dl
rm
imghdr.html
13456
0644
edit
dl
rm
imp.html
48153
0644
edit
dl
rm
importlib.html
173109
0644
edit
dl
rm
index.html
67768
0644
edit
dl
rm
inspect.html
130355
0644
edit
dl
rm
internet.html
31087
0644
edit
dl
rm
intro.html
9904
0644
edit
dl
rm
io.html
122685
0644
edit
dl
rm
ipaddress.html
105873
0644
edit
dl
rm
ipc.html
33743
0644
edit
dl
rm
itertools.html
132824
0644
edit
dl
rm
json.html
81078
0644
edit
dl
rm
keyword.html
8918
0644
edit
dl
rm
language.html
13648
0644
edit
dl
rm
linecache.html
13492
0644
edit
dl
rm
locale.html
61540
0644
edit
dl
rm
logging.config.html
85489
0644
edit
dl
rm
logging.handlers.html
112397
0644
edit
dl
rm
logging.html
134850
0644
edit
dl
rm
lzma.html
56484
0644
edit
dl
rm
macpath.html
9257
0644
edit
dl
rm
mailbox.html
157315
0644
edit
dl
rm
mailcap.html
14676
0644
edit
dl
rm
markup.html
19356
0644
edit
dl
rm
marshal.html
18317
0644
edit
dl
rm
math.html
53661
0644
edit
dl
rm
mimetypes.html
31410
0644
edit
dl
rm
misc.html
8123
0644
edit
dl
rm
mm.html
10022
0644
edit
dl
rm
mmap.html
34294
0644
edit
dl
rm
modulefinder.html
18559
0644
edit
dl
rm
modules.html
10914
0644
edit
dl
rm
msilib.html
57205
0644
edit
dl
rm
msvcrt.html
21989
0644
edit
dl
rm
multiprocessing.html
365487
0644
edit
dl
rm
netdata.html
17470
0644
edit
dl
rm
netrc.html
14568
0644
edit
dl
rm
nis.html
11659
0644
edit
dl
rm
nntplib.html
69601
0644
edit
dl
rm
numbers.html
41432
0644
edit
dl
rm
numeric.html
15535
0644
edit
dl
rm
operator.html
81460
0644
edit
dl
rm
optparse.html
249942
0644
edit
dl
rm
os.html
398039
0644
edit
dl
rm
os.path.html
53818
0644
edit
dl
rm
ossaudiodev.html
47947
0644
edit
dl
rm
othergui.html
10256
0644
edit
dl
rm
parser.html
42408
0644
edit
dl
rm
pathlib.html
116726
0644
edit
dl
rm
pdb.html
52661
0644
edit
dl
rm
persistence.html
15281
0644
edit
dl
rm
pickle.html
115052
0644
edit
dl
rm
pickletools.html
17094
0644
edit
dl
rm
pipes.html
15991
0644
edit
dl
rm
pkgutil.html
31878
0644
edit
dl
rm
platform.html
33728
0644
edit
dl
rm
plistlib.html
29290
0644
edit
dl
rm
poplib.html
30940
0644
edit
dl
rm
posix.html
17608
0644
edit
dl
rm
pprint.html
41969
0644
edit
dl
rm
profile.html
71848
0644
edit
dl
rm
pty.html
17594
0644
edit
dl
rm
pwd.html
13098
0644
edit
dl
rm
pyclbr.html
16520
0644
edit
dl
rm
pydoc.html
15991
0644
edit
dl
rm
pyexpat.html
88938
0644
edit
dl
rm
python.html
17133
0644
edit
dl
rm
py_compile.html
15508
0644
edit
dl
rm
queue.html
28199
0644
edit
dl
rm
quopri.html
13858
0644
edit
dl
rm
random.html
60646
0644
edit
dl
rm
re.html
191176
0644
edit
dl
rm
readline.html
42133
0644
edit
dl
rm
reprlib.html
24964
0644
edit
dl
rm
resource.html
36552
0644
edit
dl
rm
rlcompleter.html
14392
0644
edit
dl
rm
runpy.html
26607
0644
edit
dl
rm
sched.html
20034
0644
edit
dl
rm
secrets.html
24734
0644
edit
dl
rm
select.html
62819
0644
edit
dl
rm
selectors.html
35845
0644
edit
dl
rm
shelve.html
28777
0644
edit
dl
rm
shlex.html
48979
0644
edit
dl
rm
shutil.html
74207
0644
edit
dl
rm
signal.html
55064
0644
edit
dl
rm
site.html
32242
0644
edit
dl
rm
smtpd.html
35892
0644
edit
dl
rm
smtplib.html
68433
0644
edit
dl
rm
sndhdr.html
12439
0644
edit
dl
rm
socket.html
196077
0644
edit
dl
rm
socketserver.html
81918
0644
edit
dl
rm
spwd.html
12328
0644
edit
dl
rm
sqlite3.html
161872
0644
edit
dl
rm
ssl.html
266327
0644
edit
dl
rm
stat.html
44722
0644
edit
dl
rm
statistics.html
50050
0644
edit
dl
rm
stdtypes.html
465658
0644
edit
dl
rm
string.html
95262
0644
edit
dl
rm
stringprep.html
18654
0644
edit
dl
rm
struct.html
51100
0644
edit
dl
rm
subprocess.html
141926
0644
edit
dl
rm
sunau.html
31757
0644
edit
dl
rm
superseded.html
13781
0644
edit
dl
rm
symbol.html
8848
0644
edit
dl
rm
symtable.html
26112
0644
edit
dl
rm
sys.html
141670
0644
edit
dl
rm
sysconfig.html
30259
0644
edit
dl
rm
syslog.html
21026
0644
edit
dl
rm
tabnanny.html
12269
0644
edit
dl
rm
tarfile.html
96758
0644
edit
dl
rm
telnetlib.html
30409
0644
edit
dl
rm
tempfile.html
41394
0644
edit
dl
rm
termios.html
18181
0644
edit
dl
rm
test.html
78555
0644
edit
dl
rm
text.html
13786
0644
edit
dl
rm
textwrap.html
37998
0644
edit
dl
rm
threading.html
103464
0644
edit
dl
rm
time.html
79629
0644
edit
dl
rm
timeit.html
45249
0644
edit
dl
rm
tk.html
23299
0644
edit
dl
rm
tkinter.html
82932
0644
edit
dl
rm
tkinter.scrolledtext.html
9957
0644
edit
dl
rm
tkinter.tix.html
51858
0644
edit
dl
rm
tkinter.ttk.html
110673
0644
edit
dl
rm
token.html
22660
0644
edit
dl
rm
tokenize.html
32149
0644
edit
dl
rm
trace.html
29145
0644
edit
dl
rm
traceback.html
57588
0644
edit
dl
rm
tracemalloc.html
101144
0644
edit
dl
rm
tty.html
10540
0644
edit
dl
rm
turtle.html
250367
0644
edit
dl
rm
types.html
37060
0644
edit
dl
rm
typing.html
139175
0644
edit
dl
rm
undoc.html
9181
0644
edit
dl
rm
unicodedata.html
21108
0644
edit
dl
rm
unittest.html
250689
0644
edit
dl
rm
unittest.mock-examples.html
168144
0644
edit
dl
rm
unittest.mock.html
300089
0644
edit
dl
rm
unix.html
11780
0644
edit
dl
rm
urllib.error.html
14474
0644
edit
dl
rm
urllib.html
9566
0644
edit
dl
rm
urllib.parse.html
76334
0644
edit
dl
rm
urllib.request.html
177199
0644
edit
dl
rm
urllib.robotparser.html
17156
0644
edit
dl
rm
uu.html
12209
0644
edit
dl
rm
uuid.html
31957
0644
edit
dl
rm
venv.html
73909
0644
edit
dl
rm
warnings.html
50320
0644
edit
dl
rm
wave.html
29868
0644
edit
dl
rm
weakref.html
65292
0644
edit
dl
rm
webbrowser.html
26901
0644
edit
dl
rm
windows.html
10626
0644
edit
dl
rm
winreg.html
66730
0644
edit
dl
rm
winsound.html
21268
0644
edit
dl
rm
wsgiref.html
94492
0644
edit
dl
rm
xdrlib.html
33751
0644
edit
dl
rm
xml.dom.html
97570
0644
edit
dl
rm
xml.dom.minidom.html
41481
0644
edit
dl
rm
xml.dom.pulldom.html
24214
0644
edit
dl
rm
xml.etree.elementtree.html
135491
0644
edit
dl
rm
xml.html
19261
0644
edit
dl
rm
xml.sax.handler.html
42659
0644
edit
dl
rm
xml.sax.html
25515
0644
edit
dl
rm
xml.sax.reader.html
45869
0644
edit
dl
rm
xml.sax.utils.html
16928
0644
edit
dl
rm
xmlrpc.client.html
71947
0644
edit
dl
rm
xmlrpc.html
8535
0644
edit
dl
rm
xmlrpc.server.html
49195
0644
edit
dl
rm
zipapp.html
45105
0644
edit
dl
rm
zipfile.html
80039
0644
edit
dl
rm
zipimport.html
23052
0644
edit
dl
rm
zlib.html
34557
0644
edit
dl
rm
_dummy_thread.html
9193
0644
edit
dl
rm
_thread.html
22588
0644
edit
dl
rm
__future__.html
15792
0644
edit
dl
rm
__main__.html
9019
0644
edit
dl
rm
Edit:
/usr/share/doc/python3-docs/html/library/parser.html
(42408B)
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="X-UA-Compatible" content="IE=Edge" /> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>32.1. parser — Access Python parse trees — Python 3.6.7 documentation</title> <link rel="stylesheet" href="../_static/pydoctheme.css" type="text/css" /> <link rel="stylesheet" href="../_static/pygments.css" type="text/css" /> <script type="text/javascript" id="documentation_options" data-url_root="../" src="../_static/documentation_options.js"></script> <script type="text/javascript" src="../_static/jquery.js"></script> <script type="text/javascript" src="../_static/underscore.js"></script> <script type="text/javascript" src="../_static/doctools.js"></script> <script type="text/javascript" src="../_static/sidebar.js"></script> <link rel="search" type="application/opensearchdescription+xml" title="Search within Python 3.6.7 documentation" href="../_static/opensearch.xml"/> <link rel="author" title="About these documents" href="../about.html" /> <link rel="index" title="Index" href="../genindex.html" /> <link rel="search" title="Search" href="../search.html" /> <link rel="copyright" title="Copyright" href="../copyright.html" /> <link rel="next" title="32.2. ast — Abstract Syntax Trees" href="ast.html" /> <link rel="prev" title="32. Python Language Services" href="language.html" /> <link rel="shortcut icon" type="image/png" href="../_static/py.png" /> <link rel="canonical" href="https://docs.python.org/3/library/parser.html" /> <script type="text/javascript" src="../_static/copybutton.js"></script> </head><body> <div class="related" role="navigation" aria-label="related navigation"> <h3>Navigation</h3> <ul> <li class="right" style="margin-right: 10px"> <a href="../genindex.html" title="General Index" accesskey="I">index</a></li> <li class="right" > <a href="../py-modindex.html" title="Python Module Index" >modules</a> |</li> <li class="right" > <a href="ast.html" title="32.2. ast — Abstract Syntax Trees" accesskey="N">next</a> |</li> <li class="right" > <a href="language.html" title="32. Python Language Services" accesskey="P">previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="https://www.python.org/">Python</a> »</li> <li> <a href="../index.html">3.6.7 Documentation</a> » </li> <li class="nav-item nav-item-1"><a href="index.html" >The Python Standard Library</a> »</li> <li class="nav-item nav-item-2"><a href="language.html" accesskey="U">32. Python Language Services</a> »</li> <li class="right"> <div class="inline-search" style="display: none" role="search"> <form class="inline-search" action="../search.html" method="get"> <input placeholder="Quick search" type="text" name="q" /> <input type="submit" value="Go" /> <input type="hidden" name="check_keywords" value="yes" /> <input type="hidden" name="area" value="default" /> </form> </div> <script type="text/javascript">$('.inline-search').show(0);</script> | </li> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body" role="main"> <div class="section" id="module-parser"> <span id="parser-access-python-parse-trees"></span><h1>32.1. <a class="reference internal" href="#module-parser" title="parser: Access parse trees for Python source code."><code class="xref py py-mod docutils literal notranslate"><span class="pre">parser</span></code></a> — Access Python parse trees<a class="headerlink" href="#module-parser" title="Permalink to this headline">¶</a></h1> <hr class="docutils" id="index-0" /> <p>The <a class="reference internal" href="#module-parser" title="parser: Access parse trees for Python source code."><code class="xref py py-mod docutils literal notranslate"><span class="pre">parser</span></code></a> module provides an interface to Python’s internal parser and byte-code compiler. The primary purpose for this interface is to allow Python code to edit the parse tree of a Python expression and create executable code from this. This is better than trying to parse and modify an arbitrary Python code fragment as a string because parsing is performed in a manner identical to the code forming the application. It is also faster.</p> <div class="admonition note"> <p class="first admonition-title">Note</p> <p class="last">From Python 2.5 onward, it’s much more convenient to cut in at the Abstract Syntax Tree (AST) generation and compilation stage, using the <a class="reference internal" href="ast.html#module-ast" title="ast: Abstract Syntax Tree classes and manipulation."><code class="xref py py-mod docutils literal notranslate"><span class="pre">ast</span></code></a> module.</p> </div> <p>There are a few things to note about this module which are important to making use of the data structures created. This is not a tutorial on editing the parse trees for Python code, but some examples of using the <a class="reference internal" href="#module-parser" title="parser: Access parse trees for Python source code."><code class="xref py py-mod docutils literal notranslate"><span class="pre">parser</span></code></a> module are presented.</p> <p>Most importantly, a good understanding of the Python grammar processed by the internal parser is required. For full information on the language syntax, refer to <a class="reference internal" href="../reference/index.html#reference-index"><span class="std std-ref">The Python Language Reference</span></a>. The parser itself is created from a grammar specification defined in the file <code class="file docutils literal notranslate"><span class="pre">Grammar/Grammar</span></code> in the standard Python distribution. The parse trees stored in the ST objects created by this module are the actual output from the internal parser when created by the <a class="reference internal" href="#parser.expr" title="parser.expr"><code class="xref py py-func docutils literal notranslate"><span class="pre">expr()</span></code></a> or <a class="reference internal" href="#parser.suite" title="parser.suite"><code class="xref py py-func docutils literal notranslate"><span class="pre">suite()</span></code></a> functions, described below. The ST objects created by <a class="reference internal" href="#parser.sequence2st" title="parser.sequence2st"><code class="xref py py-func docutils literal notranslate"><span class="pre">sequence2st()</span></code></a> faithfully simulate those structures. Be aware that the values of the sequences which are considered “correct” will vary from one version of Python to another as the formal grammar for the language is revised. However, transporting code from one Python version to another as source text will always allow correct parse trees to be created in the target version, with the only restriction being that migrating to an older version of the interpreter will not support more recent language constructs. The parse trees are not typically compatible from one version to another, whereas source code has always been forward-compatible.</p> <p>Each element of the sequences returned by <a class="reference internal" href="#parser.st2list" title="parser.st2list"><code class="xref py py-func docutils literal notranslate"><span class="pre">st2list()</span></code></a> or <a class="reference internal" href="#parser.st2tuple" title="parser.st2tuple"><code class="xref py py-func docutils literal notranslate"><span class="pre">st2tuple()</span></code></a> has a simple form. Sequences representing non-terminal elements in the grammar always have a length greater than one. The first element is an integer which identifies a production in the grammar. These integers are given symbolic names in the C header file <code class="file docutils literal notranslate"><span class="pre">Include/graminit.h</span></code> and the Python module <a class="reference internal" href="symbol.html#module-symbol" title="symbol: Constants representing internal nodes of the parse tree."><code class="xref py py-mod docutils literal notranslate"><span class="pre">symbol</span></code></a>. Each additional element of the sequence represents a component of the production as recognized in the input string: these are always sequences which have the same form as the parent. An important aspect of this structure which should be noted is that keywords used to identify the parent node type, such as the keyword <a class="reference internal" href="../reference/compound_stmts.html#if"><code class="xref std std-keyword docutils literal notranslate"><span class="pre">if</span></code></a> in an <code class="xref py py-const docutils literal notranslate"><span class="pre">if_stmt</span></code>, are included in the node tree without any special treatment. For example, the <a class="reference internal" href="../reference/compound_stmts.html#if"><code class="xref std std-keyword docutils literal notranslate"><span class="pre">if</span></code></a> keyword is represented by the tuple <code class="docutils literal notranslate"><span class="pre">(1,</span> <span class="pre">'if')</span></code>, where <code class="docutils literal notranslate"><span class="pre">1</span></code> is the numeric value associated with all <code class="xref py py-const docutils literal notranslate"><span class="pre">NAME</span></code> tokens, including variable and function names defined by the user. In an alternate form returned when line number information is requested, the same token might be represented as <code class="docutils literal notranslate"><span class="pre">(1,</span> <span class="pre">'if',</span> <span class="pre">12)</span></code>, where the <code class="docutils literal notranslate"><span class="pre">12</span></code> represents the line number at which the terminal symbol was found.</p> <p>Terminal elements are represented in much the same way, but without any child elements and the addition of the source text which was identified. The example of the <a class="reference internal" href="../reference/compound_stmts.html#if"><code class="xref std std-keyword docutils literal notranslate"><span class="pre">if</span></code></a> keyword above is representative. The various types of terminal symbols are defined in the C header file <code class="file docutils literal notranslate"><span class="pre">Include/token.h</span></code> and the Python module <a class="reference internal" href="token.html#module-token" title="token: Constants representing terminal nodes of the parse tree."><code class="xref py py-mod docutils literal notranslate"><span class="pre">token</span></code></a>.</p> <p>The ST objects are not required to support the functionality of this module, but are provided for three purposes: to allow an application to amortize the cost of processing complex parse trees, to provide a parse tree representation which conserves memory space when compared to the Python list or tuple representation, and to ease the creation of additional modules in C which manipulate parse trees. A simple “wrapper” class may be created in Python to hide the use of ST objects.</p> <p>The <a class="reference internal" href="#module-parser" title="parser: Access parse trees for Python source code."><code class="xref py py-mod docutils literal notranslate"><span class="pre">parser</span></code></a> module defines functions for a few distinct purposes. The most important purposes are to create ST objects and to convert ST objects to other representations such as parse trees and compiled code objects, but there are also functions which serve to query the type of parse tree represented by an ST object.</p> <div class="admonition seealso"> <p class="first admonition-title">See also</p> <dl class="last docutils"> <dt>Module <a class="reference internal" href="symbol.html#module-symbol" title="symbol: Constants representing internal nodes of the parse tree."><code class="xref py py-mod docutils literal notranslate"><span class="pre">symbol</span></code></a></dt> <dd>Useful constants representing internal nodes of the parse tree.</dd> <dt>Module <a class="reference internal" href="token.html#module-token" title="token: Constants representing terminal nodes of the parse tree."><code class="xref py py-mod docutils literal notranslate"><span class="pre">token</span></code></a></dt> <dd>Useful constants representing leaf nodes of the parse tree and functions for testing node values.</dd> </dl> </div> <div class="section" id="creating-st-objects"> <span id="creating-sts"></span><h2>32.1.1. Creating ST Objects<a class="headerlink" href="#creating-st-objects" title="Permalink to this headline">¶</a></h2> <p>ST objects may be created from source code or from a parse tree. When creating an ST object from source, different functions are used to create the <code class="docutils literal notranslate"><span class="pre">'eval'</span></code> and <code class="docutils literal notranslate"><span class="pre">'exec'</span></code> forms.</p> <dl class="function"> <dt id="parser.expr"> <code class="descclassname">parser.</code><code class="descname">expr</code><span class="sig-paren">(</span><em>source</em><span class="sig-paren">)</span><a class="headerlink" href="#parser.expr" title="Permalink to this definition">¶</a></dt> <dd><p>The <a class="reference internal" href="#parser.expr" title="parser.expr"><code class="xref py py-func docutils literal notranslate"><span class="pre">expr()</span></code></a> function parses the parameter <em>source</em> as if it were an input to <code class="docutils literal notranslate"><span class="pre">compile(source,</span> <span class="pre">'file.py',</span> <span class="pre">'eval')</span></code>. If the parse succeeds, an ST object is created to hold the internal parse tree representation, otherwise an appropriate exception is raised.</p> </dd></dl> <dl class="function"> <dt id="parser.suite"> <code class="descclassname">parser.</code><code class="descname">suite</code><span class="sig-paren">(</span><em>source</em><span class="sig-paren">)</span><a class="headerlink" href="#parser.suite" title="Permalink to this definition">¶</a></dt> <dd><p>The <a class="reference internal" href="#parser.suite" title="parser.suite"><code class="xref py py-func docutils literal notranslate"><span class="pre">suite()</span></code></a> function parses the parameter <em>source</em> as if it were an input to <code class="docutils literal notranslate"><span class="pre">compile(source,</span> <span class="pre">'file.py',</span> <span class="pre">'exec')</span></code>. If the parse succeeds, an ST object is created to hold the internal parse tree representation, otherwise an appropriate exception is raised.</p> </dd></dl> <dl class="function"> <dt id="parser.sequence2st"> <code class="descclassname">parser.</code><code class="descname">sequence2st</code><span class="sig-paren">(</span><em>sequence</em><span class="sig-paren">)</span><a class="headerlink" href="#parser.sequence2st" title="Permalink to this definition">¶</a></dt> <dd><p>This function accepts a parse tree represented as a sequence and builds an internal representation if possible. If it can validate that the tree conforms to the Python grammar and all nodes are valid node types in the host version of Python, an ST object is created from the internal representation and returned to the called. If there is a problem creating the internal representation, or if the tree cannot be validated, a <a class="reference internal" href="#parser.ParserError" title="parser.ParserError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ParserError</span></code></a> exception is raised. An ST object created this way should not be assumed to compile correctly; normal exceptions raised by compilation may still be initiated when the ST object is passed to <a class="reference internal" href="#parser.compilest" title="parser.compilest"><code class="xref py py-func docutils literal notranslate"><span class="pre">compilest()</span></code></a>. This may indicate problems not related to syntax (such as a <a class="reference internal" href="exceptions.html#MemoryError" title="MemoryError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">MemoryError</span></code></a> exception), but may also be due to constructs such as the result of parsing <code class="docutils literal notranslate"><span class="pre">del</span> <span class="pre">f(0)</span></code>, which escapes the Python parser but is checked by the bytecode compiler.</p> <p>Sequences representing terminal tokens may be represented as either two-element lists of the form <code class="docutils literal notranslate"><span class="pre">(1,</span> <span class="pre">'name')</span></code> or as three-element lists of the form <code class="docutils literal notranslate"><span class="pre">(1,</span> <span class="pre">'name',</span> <span class="pre">56)</span></code>. If the third element is present, it is assumed to be a valid line number. The line number may be specified for any subset of the terminal symbols in the input tree.</p> </dd></dl> <dl class="function"> <dt id="parser.tuple2st"> <code class="descclassname">parser.</code><code class="descname">tuple2st</code><span class="sig-paren">(</span><em>sequence</em><span class="sig-paren">)</span><a class="headerlink" href="#parser.tuple2st" title="Permalink to this definition">¶</a></dt> <dd><p>This is the same function as <a class="reference internal" href="#parser.sequence2st" title="parser.sequence2st"><code class="xref py py-func docutils literal notranslate"><span class="pre">sequence2st()</span></code></a>. This entry point is maintained for backward compatibility.</p> </dd></dl> </div> <div class="section" id="converting-st-objects"> <span id="converting-sts"></span><h2>32.1.2. Converting ST Objects<a class="headerlink" href="#converting-st-objects" title="Permalink to this headline">¶</a></h2> <p>ST objects, regardless of the input used to create them, may be converted to parse trees represented as list- or tuple- trees, or may be compiled into executable code objects. Parse trees may be extracted with or without line numbering information.</p> <dl class="function"> <dt id="parser.st2list"> <code class="descclassname">parser.</code><code class="descname">st2list</code><span class="sig-paren">(</span><em>st</em>, <em>line_info=False</em>, <em>col_info=False</em><span class="sig-paren">)</span><a class="headerlink" href="#parser.st2list" title="Permalink to this definition">¶</a></dt> <dd><p>This function accepts an ST object from the caller in <em>st</em> and returns a Python list representing the equivalent parse tree. The resulting list representation can be used for inspection or the creation of a new parse tree in list form. This function does not fail so long as memory is available to build the list representation. If the parse tree will only be used for inspection, <a class="reference internal" href="#parser.st2tuple" title="parser.st2tuple"><code class="xref py py-func docutils literal notranslate"><span class="pre">st2tuple()</span></code></a> should be used instead to reduce memory consumption and fragmentation. When the list representation is required, this function is significantly faster than retrieving a tuple representation and converting that to nested lists.</p> <p>If <em>line_info</em> is true, line number information will be included for all terminal tokens as a third element of the list representing the token. Note that the line number provided specifies the line on which the token <em>ends</em>. This information is omitted if the flag is false or omitted.</p> </dd></dl> <dl class="function"> <dt id="parser.st2tuple"> <code class="descclassname">parser.</code><code class="descname">st2tuple</code><span class="sig-paren">(</span><em>st</em>, <em>line_info=False</em>, <em>col_info=False</em><span class="sig-paren">)</span><a class="headerlink" href="#parser.st2tuple" title="Permalink to this definition">¶</a></dt> <dd><p>This function accepts an ST object from the caller in <em>st</em> and returns a Python tuple representing the equivalent parse tree. Other than returning a tuple instead of a list, this function is identical to <a class="reference internal" href="#parser.st2list" title="parser.st2list"><code class="xref py py-func docutils literal notranslate"><span class="pre">st2list()</span></code></a>.</p> <p>If <em>line_info</em> is true, line number information will be included for all terminal tokens as a third element of the list representing the token. This information is omitted if the flag is false or omitted.</p> </dd></dl> <dl class="function"> <dt id="parser.compilest"> <code class="descclassname">parser.</code><code class="descname">compilest</code><span class="sig-paren">(</span><em>st</em>, <em>filename='<syntax-tree>'</em><span class="sig-paren">)</span><a class="headerlink" href="#parser.compilest" title="Permalink to this definition">¶</a></dt> <dd><p id="index-1">The Python byte compiler can be invoked on an ST object to produce code objects which can be used as part of a call to the built-in <a class="reference internal" href="functions.html#exec" title="exec"><code class="xref py py-func docutils literal notranslate"><span class="pre">exec()</span></code></a> or <a class="reference internal" href="functions.html#eval" title="eval"><code class="xref py py-func docutils literal notranslate"><span class="pre">eval()</span></code></a> functions. This function provides the interface to the compiler, passing the internal parse tree from <em>st</em> to the parser, using the source file name specified by the <em>filename</em> parameter. The default value supplied for <em>filename</em> indicates that the source was an ST object.</p> <p>Compiling an ST object may result in exceptions related to compilation; an example would be a <a class="reference internal" href="exceptions.html#SyntaxError" title="SyntaxError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">SyntaxError</span></code></a> caused by the parse tree for <code class="docutils literal notranslate"><span class="pre">del</span> <span class="pre">f(0)</span></code>: this statement is considered legal within the formal grammar for Python but is not a legal language construct. The <a class="reference internal" href="exceptions.html#SyntaxError" title="SyntaxError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">SyntaxError</span></code></a> raised for this condition is actually generated by the Python byte-compiler normally, which is why it can be raised at this point by the <a class="reference internal" href="#module-parser" title="parser: Access parse trees for Python source code."><code class="xref py py-mod docutils literal notranslate"><span class="pre">parser</span></code></a> module. Most causes of compilation failure can be diagnosed programmatically by inspection of the parse tree.</p> </dd></dl> </div> <div class="section" id="queries-on-st-objects"> <span id="querying-sts"></span><h2>32.1.3. Queries on ST Objects<a class="headerlink" href="#queries-on-st-objects" title="Permalink to this headline">¶</a></h2> <p>Two functions are provided which allow an application to determine if an ST was created as an expression or a suite. Neither of these functions can be used to determine if an ST was created from source code via <a class="reference internal" href="#parser.expr" title="parser.expr"><code class="xref py py-func docutils literal notranslate"><span class="pre">expr()</span></code></a> or <a class="reference internal" href="#parser.suite" title="parser.suite"><code class="xref py py-func docutils literal notranslate"><span class="pre">suite()</span></code></a> or from a parse tree via <a class="reference internal" href="#parser.sequence2st" title="parser.sequence2st"><code class="xref py py-func docutils literal notranslate"><span class="pre">sequence2st()</span></code></a>.</p> <dl class="function"> <dt id="parser.isexpr"> <code class="descclassname">parser.</code><code class="descname">isexpr</code><span class="sig-paren">(</span><em>st</em><span class="sig-paren">)</span><a class="headerlink" href="#parser.isexpr" title="Permalink to this definition">¶</a></dt> <dd><p id="index-2">When <em>st</em> represents an <code class="docutils literal notranslate"><span class="pre">'eval'</span></code> form, this function returns true, otherwise it returns false. This is useful, since code objects normally cannot be queried for this information using existing built-in functions. Note that the code objects created by <a class="reference internal" href="#parser.compilest" title="parser.compilest"><code class="xref py py-func docutils literal notranslate"><span class="pre">compilest()</span></code></a> cannot be queried like this either, and are identical to those created by the built-in <a class="reference internal" href="functions.html#compile" title="compile"><code class="xref py py-func docutils literal notranslate"><span class="pre">compile()</span></code></a> function.</p> </dd></dl> <dl class="function"> <dt id="parser.issuite"> <code class="descclassname">parser.</code><code class="descname">issuite</code><span class="sig-paren">(</span><em>st</em><span class="sig-paren">)</span><a class="headerlink" href="#parser.issuite" title="Permalink to this definition">¶</a></dt> <dd><p>This function mirrors <a class="reference internal" href="#parser.isexpr" title="parser.isexpr"><code class="xref py py-func docutils literal notranslate"><span class="pre">isexpr()</span></code></a> in that it reports whether an ST object represents an <code class="docutils literal notranslate"><span class="pre">'exec'</span></code> form, commonly known as a “suite.” It is not safe to assume that this function is equivalent to <code class="docutils literal notranslate"><span class="pre">not</span> <span class="pre">isexpr(st)</span></code>, as additional syntactic fragments may be supported in the future.</p> </dd></dl> </div> <div class="section" id="exceptions-and-error-handling"> <span id="st-errors"></span><h2>32.1.4. Exceptions and Error Handling<a class="headerlink" href="#exceptions-and-error-handling" title="Permalink to this headline">¶</a></h2> <p>The parser module defines a single exception, but may also pass other built-in exceptions from other portions of the Python runtime environment. See each function for information about the exceptions it can raise.</p> <dl class="exception"> <dt id="parser.ParserError"> <em class="property">exception </em><code class="descclassname">parser.</code><code class="descname">ParserError</code><a class="headerlink" href="#parser.ParserError" title="Permalink to this definition">¶</a></dt> <dd><p>Exception raised when a failure occurs within the parser module. This is generally produced for validation failures rather than the built-in <a class="reference internal" href="exceptions.html#SyntaxError" title="SyntaxError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">SyntaxError</span></code></a> raised during normal parsing. The exception argument is either a string describing the reason of the failure or a tuple containing a sequence causing the failure from a parse tree passed to <a class="reference internal" href="#parser.sequence2st" title="parser.sequence2st"><code class="xref py py-func docutils literal notranslate"><span class="pre">sequence2st()</span></code></a> and an explanatory string. Calls to <a class="reference internal" href="#parser.sequence2st" title="parser.sequence2st"><code class="xref py py-func docutils literal notranslate"><span class="pre">sequence2st()</span></code></a> need to be able to handle either type of exception, while calls to other functions in the module will only need to be aware of the simple string values.</p> </dd></dl> <p>Note that the functions <a class="reference internal" href="#parser.compilest" title="parser.compilest"><code class="xref py py-func docutils literal notranslate"><span class="pre">compilest()</span></code></a>, <a class="reference internal" href="#parser.expr" title="parser.expr"><code class="xref py py-func docutils literal notranslate"><span class="pre">expr()</span></code></a>, and <a class="reference internal" href="#parser.suite" title="parser.suite"><code class="xref py py-func docutils literal notranslate"><span class="pre">suite()</span></code></a> may raise exceptions which are normally raised by the parsing and compilation process. These include the built in exceptions <a class="reference internal" href="exceptions.html#MemoryError" title="MemoryError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">MemoryError</span></code></a>, <a class="reference internal" href="exceptions.html#OverflowError" title="OverflowError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">OverflowError</span></code></a>, <a class="reference internal" href="exceptions.html#SyntaxError" title="SyntaxError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">SyntaxError</span></code></a>, and <a class="reference internal" href="exceptions.html#SystemError" title="SystemError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">SystemError</span></code></a>. In these cases, these exceptions carry all the meaning normally associated with them. Refer to the descriptions of each function for detailed information.</p> </div> <div class="section" id="st-objects"> <span id="id1"></span><h2>32.1.5. ST Objects<a class="headerlink" href="#st-objects" title="Permalink to this headline">¶</a></h2> <p>Ordered and equality comparisons are supported between ST objects. Pickling of ST objects (using the <a class="reference internal" href="pickle.html#module-pickle" title="pickle: Convert Python objects to streams of bytes and back."><code class="xref py py-mod docutils literal notranslate"><span class="pre">pickle</span></code></a> module) is also supported.</p> <dl class="data"> <dt id="parser.STType"> <code class="descclassname">parser.</code><code class="descname">STType</code><a class="headerlink" href="#parser.STType" title="Permalink to this definition">¶</a></dt> <dd><p>The type of the objects returned by <a class="reference internal" href="#parser.expr" title="parser.expr"><code class="xref py py-func docutils literal notranslate"><span class="pre">expr()</span></code></a>, <a class="reference internal" href="#parser.suite" title="parser.suite"><code class="xref py py-func docutils literal notranslate"><span class="pre">suite()</span></code></a> and <a class="reference internal" href="#parser.sequence2st" title="parser.sequence2st"><code class="xref py py-func docutils literal notranslate"><span class="pre">sequence2st()</span></code></a>.</p> </dd></dl> <p>ST objects have the following methods:</p> <dl class="method"> <dt id="parser.ST.compile"> <code class="descclassname">ST.</code><code class="descname">compile</code><span class="sig-paren">(</span><em>filename='<syntax-tree>'</em><span class="sig-paren">)</span><a class="headerlink" href="#parser.ST.compile" title="Permalink to this definition">¶</a></dt> <dd><p>Same as <code class="docutils literal notranslate"><span class="pre">compilest(st,</span> <span class="pre">filename)</span></code>.</p> </dd></dl> <dl class="method"> <dt id="parser.ST.isexpr"> <code class="descclassname">ST.</code><code class="descname">isexpr</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#parser.ST.isexpr" title="Permalink to this definition">¶</a></dt> <dd><p>Same as <code class="docutils literal notranslate"><span class="pre">isexpr(st)</span></code>.</p> </dd></dl> <dl class="method"> <dt id="parser.ST.issuite"> <code class="descclassname">ST.</code><code class="descname">issuite</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#parser.ST.issuite" title="Permalink to this definition">¶</a></dt> <dd><p>Same as <code class="docutils literal notranslate"><span class="pre">issuite(st)</span></code>.</p> </dd></dl> <dl class="method"> <dt id="parser.ST.tolist"> <code class="descclassname">ST.</code><code class="descname">tolist</code><span class="sig-paren">(</span><em>line_info=False</em>, <em>col_info=False</em><span class="sig-paren">)</span><a class="headerlink" href="#parser.ST.tolist" title="Permalink to this definition">¶</a></dt> <dd><p>Same as <code class="docutils literal notranslate"><span class="pre">st2list(st,</span> <span class="pre">line_info,</span> <span class="pre">col_info)</span></code>.</p> </dd></dl> <dl class="method"> <dt id="parser.ST.totuple"> <code class="descclassname">ST.</code><code class="descname">totuple</code><span class="sig-paren">(</span><em>line_info=False</em>, <em>col_info=False</em><span class="sig-paren">)</span><a class="headerlink" href="#parser.ST.totuple" title="Permalink to this definition">¶</a></dt> <dd><p>Same as <code class="docutils literal notranslate"><span class="pre">st2tuple(st,</span> <span class="pre">line_info,</span> <span class="pre">col_info)</span></code>.</p> </dd></dl> </div> <div class="section" id="example-emulation-of-compile"> <h2>32.1.6. Example: Emulation of <a class="reference internal" href="functions.html#compile" title="compile"><code class="xref py py-func docutils literal notranslate"><span class="pre">compile()</span></code></a><a class="headerlink" href="#example-emulation-of-compile" title="Permalink to this headline">¶</a></h2> <p>While many useful operations may take place between parsing and bytecode generation, the simplest operation is to do nothing. For this purpose, using the <a class="reference internal" href="#module-parser" title="parser: Access parse trees for Python source code."><code class="xref py py-mod docutils literal notranslate"><span class="pre">parser</span></code></a> module to produce an intermediate data structure is equivalent to the code</p> <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">code</span> <span class="o">=</span> <span class="nb">compile</span><span class="p">(</span><span class="s1">'a + 5'</span><span class="p">,</span> <span class="s1">'file.py'</span><span class="p">,</span> <span class="s1">'eval'</span><span class="p">)</span> <span class="gp">>>> </span><span class="n">a</span> <span class="o">=</span> <span class="mi">5</span> <span class="gp">>>> </span><span class="nb">eval</span><span class="p">(</span><span class="n">code</span><span class="p">)</span> <span class="go">10</span> </pre></div> </div> <p>The equivalent operation using the <a class="reference internal" href="#module-parser" title="parser: Access parse trees for Python source code."><code class="xref py py-mod docutils literal notranslate"><span class="pre">parser</span></code></a> module is somewhat longer, and allows the intermediate internal parse tree to be retained as an ST object:</p> <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">parser</span> <span class="gp">>>> </span><span class="n">st</span> <span class="o">=</span> <span class="n">parser</span><span class="o">.</span><span class="n">expr</span><span class="p">(</span><span class="s1">'a + 5'</span><span class="p">)</span> <span class="gp">>>> </span><span class="n">code</span> <span class="o">=</span> <span class="n">st</span><span class="o">.</span><span class="n">compile</span><span class="p">(</span><span class="s1">'file.py'</span><span class="p">)</span> <span class="gp">>>> </span><span class="n">a</span> <span class="o">=</span> <span class="mi">5</span> <span class="gp">>>> </span><span class="nb">eval</span><span class="p">(</span><span class="n">code</span><span class="p">)</span> <span class="go">10</span> </pre></div> </div> <p>An application which needs both ST and code objects can package this code into readily available functions:</p> <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">parser</span> <span class="k">def</span> <span class="nf">load_suite</span><span class="p">(</span><span class="n">source_string</span><span class="p">):</span> <span class="n">st</span> <span class="o">=</span> <span class="n">parser</span><span class="o">.</span><span class="n">suite</span><span class="p">(</span><span class="n">source_string</span><span class="p">)</span> <span class="k">return</span> <span class="n">st</span><span class="p">,</span> <span class="n">st</span><span class="o">.</span><span class="n">compile</span><span class="p">()</span> <span class="k">def</span> <span class="nf">load_expression</span><span class="p">(</span><span class="n">source_string</span><span class="p">):</span> <span class="n">st</span> <span class="o">=</span> <span class="n">parser</span><span class="o">.</span><span class="n">expr</span><span class="p">(</span><span class="n">source_string</span><span class="p">)</span> <span class="k">return</span> <span class="n">st</span><span class="p">,</span> <span class="n">st</span><span class="o">.</span><span class="n">compile</span><span class="p">()</span> </pre></div> </div> </div> </div> </div> </div> </div> <div class="sphinxsidebar" role="navigation" aria-label="main navigation"> <div class="sphinxsidebarwrapper"> <h3><a href="../contents.html">Table Of Contents</a></h3> <ul> <li><a class="reference internal" href="#">32.1. <code class="docutils literal notranslate"><span class="pre">parser</span></code> — Access Python parse trees</a><ul> <li><a class="reference internal" href="#creating-st-objects">32.1.1. Creating ST Objects</a></li> <li><a class="reference internal" href="#converting-st-objects">32.1.2. Converting ST Objects</a></li> <li><a class="reference internal" href="#queries-on-st-objects">32.1.3. Queries on ST Objects</a></li> <li><a class="reference internal" href="#exceptions-and-error-handling">32.1.4. Exceptions and Error Handling</a></li> <li><a class="reference internal" href="#st-objects">32.1.5. ST Objects</a></li> <li><a class="reference internal" href="#example-emulation-of-compile">32.1.6. Example: Emulation of <code class="docutils literal notranslate"><span class="pre">compile()</span></code></a></li> </ul> </li> </ul> <h4>Previous topic</h4> <p class="topless"><a href="language.html" title="previous chapter">32. Python Language Services</a></p> <h4>Next topic</h4> <p class="topless"><a href="ast.html" title="next chapter">32.2. <code class="docutils literal notranslate"><span class="pre">ast</span></code> — Abstract Syntax Trees</a></p> <div role="note" aria-label="source link"> <h3>This Page</h3> <ul class="this-page-menu"> <li><a href="../bugs.html">Report a Bug</a></li> <li> <a href="https://github.com/python/cpython/blob/3.6/Doc/library/parser.rst" rel="nofollow">Show Source </a> </li> </ul> </div> </div> </div> <div class="clearer"></div> </div> <div class="related" role="navigation" aria-label="related navigation"> <h3>Navigation</h3> <ul> <li class="right" style="margin-right: 10px"> <a href="../genindex.html" title="General Index" >index</a></li> <li class="right" > <a href="../py-modindex.html" title="Python Module Index" >modules</a> |</li> <li class="right" > <a href="ast.html" title="32.2. ast — Abstract Syntax Trees" >next</a> |</li> <li class="right" > <a href="language.html" title="32. Python Language Services" >previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="https://www.python.org/">Python</a> »</li> <li> <a href="../index.html">3.6.7 Documentation</a> » </li> <li class="nav-item nav-item-1"><a href="index.html" >The Python Standard Library</a> »</li> <li class="nav-item nav-item-2"><a href="language.html" >32. Python Language Services</a> »</li> <li class="right"> <div class="inline-search" style="display: none" role="search"> <form class="inline-search" action="../search.html" method="get"> <input placeholder="Quick search" type="text" name="q" /> <input type="submit" value="Go" /> <input type="hidden" name="check_keywords" value="yes" /> <input type="hidden" name="area" value="default" /> </form> </div> <script type="text/javascript">$('.inline-search').show(0);</script> | </li> </ul> </div> <div class="footer"> © <a href="../copyright.html">Copyright</a> 2001-2023, Python Software Foundation. <br /> The Python Software Foundation is a non-profit corporation. <a href="https://www.python.org/psf/donations/">Please donate.</a> <br /> Last updated on Dec 18, 2023. <a href="../bugs.html">Found a bug</a>? <br /> Created using <a href="http://sphinx.pocoo.org/">Sphinx</a> 1.7.6. </div> </body> </html>
Save
cmd:
run