"""Parse a Python file and retrieve classes and methods.
Parse enough of a Python file to recognize class and method
definitions and to find out the superclasses of a class.
The interface consists of a single function:
readmodule(module, path)
module is the name of a Python module, path is an optional list of
directories where the module is to be searched. If present, path is
prepended to the system search path sys.path.
The return value is a dictionary. The keys of the dictionary are
the names of the classes defined in the module (including classes
that are defined via the from XXX import YYY construct). The values
are class instances of the class Class defined here.
A class is described by the class Class in this module. Instances
of this class have the following instance variables:
name -- the name of the class
super -- a list of super classes (Class instances)
methods -- a dictionary of methods
file -- the file in which the class was defined
lineno -- the line in the file on which the class statement occurred
The dictionary of methods uses the method names as keys and the line
numbers on which the method was defined as values.
If the name of a super class is not recognized, the corresponding
entry in the list of super classes is not a class instance but a
string giving the name of the super class. Since import statements
are recognized and imported modules are scanned as well, this
shouldn't happen often.
BUGS
- Continuation lines are not dealt with at all.
- While triple-quoted strings won't confuse it, lines that look like
def, class, import or "from ... import" stmts inside backslash-continued
single-quoted strings are treated like code. The expense of stopping
that isn't worth it.
- Code that doesn't pass tabnanny or python -t will confuse it, unless
you set the module TABWIDTH vrbl (default 8) to the correct tab width
for the file.
PACKAGE RELATED BUGS
- If you have a package and a module inside that or another package
with the same name, module caching doesn't work properly since the
key is the base name of the module/package.
- The only entry that is returned when you readmodule a package is a
__path__ whose value is a list which confuses certain class browsers.
- When code does:
from package import subpackage
class MyClass(subpackage.SuperClass):
...
It can't locate the parent. It probably needs to have the same
hairy logic that the import locator already does. (This logic
exists coded in Python in the freeze package.)
"""
import os
import sys
import imp
import re
import string
TABWIDTH = 8
_getnext = re.compile(r"""
(?P<String>
\""" [^"\\]* (?:
(?: \\. | "(?!"") )
[^"\\]*
)*
\"""
| ''' [^'\\]* (?:
(?: \\. | '(?!'') )
[^'\\]*
)*
'''
)
| (?P<Method>
^
(?P<MethodIndent> [ \t]* )
def [ \t]+
(?P<MethodName> [a-zA-Z_] \w* )
[ \t]* \(
)
| (?P<Class>
^
(?P<ClassIndent> [ \t]* )
class [ \t]+
(?P<ClassName> [a-zA-Z_] \w* )
[ \t]*
(?P<ClassSupers> \( [^)\n]* \) )?
[ \t]* :
)
| (?P<Import>
^ import [ \t]+
(?P<ImportList> [^#;\n]+ )
)
| (?P<ImportFrom>
^ from [ \t]+
(?P<ImportFromPath>
[a-zA-Z_] \w*
(?:
[ \t]* \. [ \t]* [a-zA-Z_] \w*
)*
)
[ \t]+
import [ \t]+
(?P<ImportFromList> [^#;\n]+ )
)
""", re.VERBOSE | re.DOTALL | re.MULTILINE).search
_modules = {} # cache of modules we've seen
# each Python class is represented by an instance of this class
class Class:
'''Class to represent a Python class.'''
def __init__(self, module, name, super, file, lineno):
self.module = module
self.name = name
if super is None:
super = []
self.super = super
self.methods = {}
self.file = file
self.lineno = lineno
def _addmethod(self, name, lineno):
self.methods[name] = lineno
class Function(Class):
'''Class to represent a top-level Python function'''
def __init__(self, module, name, file, lineno):
Class.__init__(self, module, name, None, file, lineno)
def _addmethod(self, name, lineno):
assert 0, "Function._addmethod() shouldn't be called"
def readmodule(module, path=[], inpackage=0):
'''Backwards compatible interface.
Like readmodule_ex() but strips Function objects from the import
resulting dictionary.'''
dict = readmodule_ex(module, path, inpackage)
res = {}
for key, value in dict.items():
if not isinstance(value, Function):
res[key] = value
return res
def readmodule_ex(module, path=[], inpackage=0):
'''Read a module file and return a dictionary of classes.
Search for MODULE in PATH and sys.path, read and parse the
module and return a dictionary with one entry for each class
found in the module.'''
dict = {}
i = string.rfind(module, '.')
if i >= 0:
# Dotted module name
package = string.strip(module[:i])
submodule = string.strip(module[i+1:])
parent = readmodule(package, path, inpackage)
child = readmodule(submodule, parent['__path__'], 1)
return child
if _modules.has_key(module):
# we've seen this module before...
return _modules[module]
if module in sys.builtin_module_names:
# this is a built-in module
_modules[module] = dict
return dict
# search the path for the module
f = None
if inpackage:
try:
f, file, (suff, mode, type) = \
imp.find_module(module, path)
except ImportError:
f = None
if f is None:
fullpath = list(path) + sys.path
f, file, (suff, mode, type) = imp.find_module(module, fullpath)
if type == imp.PKG_DIRECTORY:
dict['__path__'] = [file]
_modules[module] = dict
path = [file] + path
f, file, (suff, mode, type) = \
imp.find_module('__init__', [file])
if type != imp.PY_SOURCE:
# not Python source, can't do anything with this module
f.close()
_modules[module] = dict
return dict
_modules[module] = dict
imports = []
classstack = [] # stack of (class, indent) pairs
src = f.read()
f.close()
# To avoid having to stop the regexp at each newline, instead
# when we need a line number we simply string.count the number of
# newlines in the string since the last time we did this; i.e.,
# lineno = lineno + \
# string.count(src, '\n', last_lineno_pos, here)
# last_lineno_pos = here
countnl = string.count
lineno, last_lineno_pos = 1, 0
i = 0
while 1:
m = _getnext(src, i)
if not m:
break
start, i = m.span()
if m.start("Method") >= 0:
# found a method definition or function
thisindent = _indent(m.group("MethodIndent"))
meth_name = m.group("MethodName")
lineno = lineno + \
countnl(src, '\n',
last_lineno_pos, start)
last_lineno_pos = start
# close all classes indented at least as much
while classstack and \
classstack[-1][1] >= thisindent:
del classstack[-1]
if classstack:
# it's a class method
cur_class = classstack[-1][0]
cur_class._addmethod(meth_name, lineno)
else:
# it's a function
f = Function(module, meth_name,
file, lineno)
dict[meth_name] = f
elif m.start("String") >= 0:
pass
elif m.start("Class") >= 0:
# we found a class definition
thisindent = _indent(m.group("ClassIndent"))
# close all classes indented at least as much
while classstack and \
classstack[-1][1] >= thisindent:
del classstack[-1]
lineno = lineno + \
countnl(src, '\n', last_lineno_pos, start)
last_lineno_pos = start
class_name = m.group("ClassName")
inherit = m.group("ClassSupers")
if inherit:
# the class inherits from other classes
inherit = string.strip(inherit[1:-1])
names = []
for n in string.splitfields(inherit, ','):
n = string.strip(n)
if dict.has_key(n):
# we know this super class
n = dict[n]
else:
c = string.splitfields(n, '.')
if len(c) > 1:
# super class
# is of the
# form module.class:
# look in
# module for class
m = c[-2]
c = c[-1]
if _modules.has_key(m):
d = _modules[m]
if d.has_key(c):
n = d[c]
names.append(n)
inherit = names
# remember this class
cur_class = Class(module, class_name, inherit,
file, lineno)
dict[class_name] = cur_class
classstack.append((cur_class, thisindent))
elif m.start("Import") >= 0:
# import module
for n in string.split(m.group("ImportList"), ','):
n = string.strip(n)
try:
# recursively read the imported module
d = readmodule(n, path, inpackage)
except:
##print 'module', n, 'not found'
pass
elif m.start("ImportFrom") >= 0:
# from module import stuff
mod = m.group("ImportFromPath")
names = string.split(m.group("ImportFromList"), ',')
try:
# recursively read the imported module
d = readmodule(mod, path, inpackage)
except:
##print 'module', mod, 'not found'
continue
# add any classes that were defined in the
# imported module to our name space if they
# were mentioned in the list
for n in names:
n = string.strip(n)
if d.has_key(n):
dict[n] = d[n]
elif n == '*':
# only add a name if not
# already there (to mimic what
# Python does internally)
# also don't add names that
# start with _
for n in d.keys():
if n[0] != '_' and \
not dict.has_key(n):
dict[n] = d[n]
else:
assert 0, "regexp _getnext found something unexpected"
return dict
def _indent(ws, _expandtabs=string.expandtabs):
return len(_expandtabs(ws, TABWIDTH))
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