"""
Fixer for import statements, with a __future__ import line.
Based on lib2to3/fixes/fix_import.py, but extended slightly so it also
supports Cython modules.
If spam is being imported from the local directory, this import:
from spam import eggs
becomes:
from __future__ import absolute_import
from .spam import eggs
and this import:
import spam
becomes:
from __future__ import absolute_import
from . import spam
"""
from os.path import dirname, join, exists, sep
from lib2to3.fixes.fix_import import FixImport
from lib2to3.fixer_util import FromImport, syms
from lib2to3.fixes.fix_import import traverse_imports
from libfuturize.fixer_util import future_import
class FixAbsoluteImport(FixImport):
run_order = 9
def transform(self, node, results):
"""
Copied from FixImport.transform(), but with this line added in
any modules that had implicit relative imports changed:
from __future__ import absolute_import"
"""
if self.skip:
return
imp = results['imp']
if node.type == syms.import_from:
# Some imps are top-level (eg: 'import ham')
# some are first level (eg: 'import ham.eggs')
# some are third level (eg: 'import ham.eggs as spam')
# Hence, the loop
while not hasattr(imp, 'value'):
imp = imp.children[0]
if self.probably_a_local_import(imp.value):
imp.value = u"." + imp.value
imp.changed()
future_import(u"absolute_import", node)
else:
have_local = False
have_absolute = False
for mod_name in traverse_imports(imp):
if self.probably_a_local_import(mod_name):
have_local = True
else:
have_absolute = True
if have_absolute:
if have_local:
# We won't handle both sibling and absolute imports in the
# same statement at the moment.
self.warning(node, "absolute and local imports together")
return
new = FromImport(u".", [imp])
new.prefix = node.prefix
future_import(u"absolute_import", node)
return new
def probably_a_local_import(self, imp_name):
"""
Like the corresponding method in the base class, but this also
supports Cython modules.
"""
if imp_name.startswith(u"."):
# Relative imports are certainly not local imports.
return False
imp_name = imp_name.split(u".", 1)[0]
base_path = dirname(self.filename)
base_path = join(base_path, imp_name)
# If there is no __init__.py next to the file its not in a package
# so can't be a relative import.
if not exists(join(dirname(base_path), "__init__.py")):
return False
for ext in [".py", sep, ".pyc", ".so", ".sl", ".pyd", ".pyx"]:
if exists(base_path + ext):
return True
return False
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