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@omaraboumrad omaraboumrad/astlookup.py
Last active Oct 9, 2015

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What would you like to do?
Run static checks through various ast paths
import sys
import ast
is_if = lambda s: isinstance(s, ast.If)
is_for = lambda s: isinstance(s, ast.For)
is_call = lambda s: isinstance(s, ast.Call)
call_name_is = lambda s, n: is_call(s) and hasattr(s.func, 'attr') and s.func.attr == n
has_else = lambda s: is_if(s) and len(s.orelse) > 0
is_return = lambda s: isinstance(s, ast.Return)
is_name = lambda s: isinstance(s, ast.Name)
is_boolean = lambda n: is_name(n) and n.id in ('True', 'False')
def find_for_x_in_y_keys(tree):
"""
>>> code = '''for x in y.keys():
... pass
... '''
>>> tree = ast.parse(code)
>>> assert find_for_x_in_y_keys(tree) == [1]
>>> code = '''for x in y:
... pass
... '''
>>> tree = ast.parse(code)
>>> assert find_for_x_in_y_keys(tree) == []
"""
found = []
for node in ast.walk(tree):
checks = is_for(node) \
and call_name_is(node.iter, 'keys')
if checks:
found.append(node.lineno)
return found
def find_if_x_ret_bool_else_ret_bool(tree):
"""
>>> code = '''if foo:
... print True
... '''
>>> tree = ast.parse(code)
>>> assert find_if_x_ret_bool_else_ret_bool(tree) == []
>>> code = '''if foo:
... return False
... else:
... return True
... '''
>>> tree = ast.parse(code)
>>> assert find_if_x_ret_bool_else_ret_bool(tree) == [1]
"""
found = []
for node in ast.walk(tree):
checks = is_if(node) \
and is_return(node.body[0]) \
and is_boolean(node.body[0].value) \
and has_else(node) \
and is_return(node.orelse[0])\
and is_boolean(node.orelse[0].value)
if checks:
found.append(node.lineno)
return found
def lookup_paths_for_file(code_file, ast_paths):
try:
tree = ast.parse(open(code_file).read())
except: # Catch all, don't care.
print "Error: Could not parse: {}".format(code_file)
return
for friendly, checker in ast_paths.items():
adherance = checker(tree)
for lineno in adherance:
print '{}: {}: {}'.format(
code_file,
friendly,
lineno)
if __name__ == '__main__':
AST_PATHS = {
'If/RetBool/Else/RetBool': find_if_x_ret_bool_else_ret_bool,
'For/In/DictKeys': find_for_x_in_y_keys
}
lookup_paths_for_file(sys.argv[1], AST_PATHS)
@omaraboumrad

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omaraboumrad commented Oct 9, 2015

This gist grew into a package found here: https://github.com/omaraboumrad/mastool

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