""" Fixer for imports of itertools.(imap|ifilter|izip|ifilterfalse) """
# Local imports
from lib2to3 import fixer_base
from lib2to3.fixer_util import BlankLine, syms, token
class FixItertoolsImports(fixer_base.BaseFix):
BM_compatible = True
PATTERN = """
import_from< 'from' 'itertools' 'import' imports=any >
""" %(locals())
def transform(self, node, results):
imports = results['imports']
if imports.type == syms.import_as_name or not imports.children:
children = [imports]
else:
children = imports.children
for child in children[::2]:
if child.type == token.NAME:
member = child.value
name_node = child
elif child.type == token.STAR:
# Just leave the import as is.
return
else:
assert child.type == syms.import_as_name
name_node = child.children[0]
member_name = name_node.value
if member_name in ('imap', 'izip', 'ifilter'):
child.value = None
child.remove()
elif member_name in ('ifilterfalse', 'izip_longest'):
node.changed()
name_node.value = ('filterfalse' if member_name[1] == 'f'
else 'zip_longest')
# Make sure the import statement is still sane
children = imports.children[:] or [imports]
remove_comma = True
for child in children:
if remove_comma and child.type == token.COMMA:
child.remove()
else:
remove_comma ^= True
while children and children[-1].type == token.COMMA:
children.pop().remove()
# If there are no imports left, just get rid of the entire statement
if (not (imports.children or getattr(imports, 'value', None)) or
imports.parent is None):
p = node.prefix
node = BlankLine()
node.prefix = p
return node
