"""Python AST pretty-printer.
Copyright(C) 2007, Martin Blais <blais@furius.ca>
This module exports a function that can be used to print a human-readable
version of the AST.
This code is downloaded verbatim from:
http://code.activestate.com/recipes/533146/
"""
__author__ = 'Martin Blais <blais@furius.ca>'
import sys
__all__ = ('printAst','getAststr')
from StringIO import StringIO
def getAststr(astmod, ast, indent=' ', initlevel=0):
"Pretty-print an AST to the given output stream."
stream = StringIO()
rec_node(astmod, ast, initlevel, indent, stream.write)
stream.write('\n')
stream.seek(0)
return stream.read()
def printAst(astmod, ast, indent=' ', stream=sys.stdout, initlevel=0):
"Pretty-print an AST to the given output stream."
rec_node(astmod, ast, initlevel, indent, stream.write)
stream.write('\n')
stream.flush()
def rec_node(astmod, node, level, indent, write):
"Recurse through a node, pretty-printing it."
pfx = indent * level
if isinstance(node, astmod.Node):
write(pfx)
write(node.__class__.__name__)
write('(')
i = 0
for child in node.getChildren():
if not isinstance(child, astmod.Node):
continue
if i != 0:
write(',')
write('\n')
rec_node(astmod, child, level+1, indent, write)
i += 1
if i == 0:
# None of the children as nodes, simply join their repr on a single
# line.
res = []
for child in node.getChildren():
res.append(repr(child))
write(', '.join(res))
else:
write('\n')
write(pfx)
write(')')
else:
write(pfx)
write(repr(node))
def main():
from compiler import ast
import optparse
parser = optparse.OptionParser(__doc__.strip())
opts, args = parser.parse_args()
if not args:
parser.error("You need to specify the name of Python files to print out.")
import compiler, traceback
for fn in args:
print '\n\n%s:\n' % fn
try:
printAst(ast, compiler.parseFile(fn), initlevel=1)
except SyntaxError, e:
traceback.print_exc()
if __name__ == '__main__':
main()
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