"""Python AST pretty-printer.
This module exports a function that can be used to print a human-readable
version of the AST.
"""
__author__ = 'Martin Blais <blais@furius.ca>'
import sys
from compiler.ast import Node
__all__ = ('printAst',)
def printAst(ast, indent=' ', stream=sys.stdout, initlevel=0):
"Pretty-print an AST to the given output stream."
rec_node(ast, initlevel, indent, stream.write)
stream.write('\n')
def rec_node(node, level, indent, write):
"Recurse through a node, pretty-printing it."
pfx = indent * level
if isinstance(node, Node):
write(pfx)
write(node.__class__.__name__)
write('(')
if any(isinstance(child, Node) for child in node.getChildren()):
for i, child in enumerate(node.getChildren()):
if i != 0:
write(',')
write('\n')
rec_node(child, level+1, indent, write)
write('\n')
write(pfx)
else:
# None of the children as nodes, simply join their repr on a single
# line.
write(', '.join(repr(child) for child in node.getChildren()))
write(')')
else:
write(pfx)
write(repr(node))
def main():
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(compiler.parseFile(fn), initlevel=1)
except SyntaxError, e:
traceback.print_exc()
if __name__ == '__main__':
main()
