def syntax(message=None, usage=None):
if message:
logger.error(message)
outmsg = ((usage or maindoc()) +
'\n\nFor usage, see: %s --help' % (sys.argv[0],))
print(outmsg, file=sys.stderr)
raise SystemExit(1)
def fix_unused_and_missing_imports(codeblock,
add_missing=True,
remove_unused="AUTOMATIC",
add_mandatory=True,
db=None,
params=None):
r"""
Check for unused and missing imports, and fix them automatically.
Also formats imports.
In the example below, C{m1} and C{m3} are unused, so are automatically
removed. C{np} was undefined, so an C{import numpy as np} was
automatically added.
>>> codeblock = PythonBlock(
... 'from foo import m1, m2, m3, m4\n'
... 'm2, m4, np.foo', filename="/tmp/foo.py")
>>> print fix_unused_and_missing_imports(codeblock, add_mandatory=False)
[PYFLYBY] /tmp/foo.py: removed unused 'from foo import m1'
[PYFLYBY] /tmp/foo.py: removed unused 'from foo import m3'
[PYFLYBY] /tmp/foo.py: added 'import numpy as np'
import numpy as np
from foo import m2, m4
m2, m4, np.foo
@type codeblock:
L{PythonBlock} or convertible (C{str})
@rtype:
L{PythonBlock}
"""
codeblock = PythonBlock(codeblock)
if remove_unused == "AUTOMATIC":
fn = codeblock.filename
remove_unused = not (fn and (fn.base == "__init__.py"
or ".pyflyby" in str(fn).split("/")))
elif remove_unused is True or remove_unused is False:
pass
else:
raise ValueError("Invalid remove_unused=%r" % (remove_unused, ))
params = ImportFormatParams(params)
db = ImportDB.interpret_arg(db, target_filename=codeblock.filename)
# Do a first pass reformatting the imports to get rid of repeated or
# shadowed imports, e.g. L1 here:
# import foo # L1
# import foo # L2
# foo # L3
codeblock = reformat_import_statements(codeblock, params=params)
filename = codeblock.filename
transformer = SourceToSourceFileImportsTransformation(codeblock)
missing_imports, unused_imports = scan_for_import_issues(
codeblock, find_unused_imports=remove_unused, parse_docstrings=True)
logger.debug("missing_imports = %r", missing_imports)
logger.debug("unused_imports = %r", unused_imports)
if remove_unused and unused_imports:
# Go through imports to remove. [This used to be organized by going
# through import blocks and removing all relevant blocks from there,
# but if one removal caused problems the whole thing would fail. The
# CPU cost of calling without_imports() multiple times isn't worth
# that.]
# TODO: don't remove unused mandatory imports. [This isn't
# implemented yet because this isn't necessary for __future__ imports
# since they aren't reported as unused, and those are the only ones we
# have by default right now.]
for lineno, imp in unused_imports:
try:
imp = transformer.remove_import(imp, lineno)
except NoSuchImportError:
logger.error(
"%s: couldn't remove import %r",
filename,
imp,
)
except LineNumberNotFoundError as e:
logger.error("%s: unused import %r on line %d not global",
filename, str(imp), e.args[0])
else:
logger.info("%s: removed unused '%s'", filename, imp)
if add_missing and missing_imports:
missing_imports.sort(key=lambda k: (k[1], k[0]))
known = db.known_imports.by_import_as
# Decide on where to put each import to be added. Find the import
# block with the longest common prefix. Tie-break by preferring later
# blocks.
added_imports = set()
for lineno, ident in missing_imports:
import_as = ident.parts[0]
try:
imports = known[import_as]
except KeyError:
logger.warning(
"%s:%s: undefined name %r and no known import for it",
filename, lineno, import_as)
continue
if len(imports) != 1:
logger.error("%s: don't know which of %r to use", filename,
imports)
continue
imp_to_add = imports[0]
if imp_to_add in added_imports:
continue
transformer.add_import(imp_to_add, lineno)
added_imports.add(imp_to_add)
logger.info("%s: added %r", filename,
imp_to_add.pretty_print().strip())
if add_mandatory:
# Todo: allow not adding to empty __init__ files?
mandatory = db.mandatory_imports.imports
for imp in mandatory:
try:
transformer.add_import(imp)
except ImportAlreadyExistsError:
pass
else:
logger.info("%s: added mandatory %r", filename,
imp.pretty_print().strip())
return transformer.output(params=params)