Add option to expand single star import #18

adhikasp · 2017-06-15T17:58:43Z

This patch add new feature to automatically expand a star
(wildcard) import to specify all names that used inside the code.

A sample code like this

from math import *
sin(1)
cos(0)

will be changed into

from math import cos, sin
sin(1)
cos(0)

Note that there are still 2 bugs regarding this feature,
which mainly caused by related upstream bug from pyflakes:

A function/names that declared but later deleted by del
command will raise a false positive that the names is
undeclared and could possibly come from a star import
(if present).
False positive undefined name after del in branch pyflakes#175
pyflakes is "inconsistent" on defining an undefined var
in case of __all__ is used (like in module API files).

from foo import * # contain function_1 and function_2

__all__ = ['function_1', 'function_2', 'function_3']

function_2() # just use it somewhere to trigger pyflake

def function_3:
    return 'something'

pyflakes will complain that function_2 is undefined and
possibly come from module foo. The import then will be
expanded into...

from foo import function_2

But then pyflakes will complain function_1 is undefined
because it's used in __all__.

Closes #14

coveralls · 2017-06-15T18:20:35Z

Coverage decreased (-98.7%) to 0.0% when pulling 0cf2a22 on adhikasp:expand-star-import into d756487 on myint:master.

adhikasp · 2017-06-15T18:43:08Z

I will look into coverage decrease

coveralls · 2017-06-16T02:04:58Z

Coverage decreased (-0.08%) to 98.583% when pulling 9a2ceec on adhikasp:expand-star-import into d756487 on myint:master.

myint

Very nice!

And thanks for catching the missing parenthesis in the documentation. I didn't notice it for 4 years! 😄

myint · 2017-06-16T03:00:20Z

autoflake.py

@@ -569,9 +607,11 @@ def _main(argv, standard_out, standard_error):
                        help='by default, only unused standard library '
                             'imports are removed; specify a comma-separated '
                             'list of additional modules/packages')
+    parser.add_argument('--expand-single-star-import', action='store_true',


~~I'm not sure what the "single" means here. Do you think the shorter --expand-star-import would make sense?~~

~~Also, I think it would better match the other options if it were plural (--expand-star-imports)~~

Oh, never mind. I think I see what this means. It only works if there is a single star import in the whole file.

How about --expand-lone-star-imports?

Yeah thats seems better

Well, I think if we want to describe it in the option name, single is better from the meaning perpective http://wikidiff.com/lone/single 😄

myint · 2017-06-16T03:03:53Z

autoflake.py

@@ -117,6 +117,20 @@ def unused_import_module_name(messages):
            if module_name:
                yield (message.lineno, module_name)

+def star_import_used_line_numbers(messages):
+    """Yield line number of star import usage"""
+    pattern = r':\ (.+)$'


pattern doesn't seem to be used anywhere.

myint · 2017-06-16T03:04:27Z

autoflake.py

+            for line_number, undefined_name, _ \
+                 in star_import_usage_undefined_name(messages):
+                undefined_names.append(undefined_name)
+            if len(undefined_names) == 0:


It might be simpler to do:

if not undefined_names:

This patch add new feature to automatically expand a star (wildcard) import to specify all names that used inside the code. A sample code like this ```python from math import * sin(1) cos(0) ``` will be changed into ```python from math import cos, sin sin(1) cos(0) ``` Note that there are still 2 bugs regarding this feature, which mainly caused by related upstream bug from pyflakes: 1. A function/names that declared but later deleted by `del` command will raise a false positive that the names is undeclared and could possibly come from a star import (if present). PyCQA/pyflakes#175 2. pyflakes is "inconsistent" on defining an undefined var in case of __all__ is used (like in module API files). ```python from foo import * # contain function_1 and function_2 __all__ = ['function_1', 'function_2', 'function_3'] function_2() # just use it somewhere to trigger pyflake def function_3: return 'something' ``` pyflakes will complain that function_2 is undefined and possibly come from module foo. The import then will be expanded into... ```python from foo import function_2 ``` But then pyflakes will complain function_1 is undefined because its used in `__all__` Closes PyCQA#14

adhikasp · 2017-06-16T04:42:49Z

All request has been amended

coveralls · 2017-06-16T04:44:45Z

Coverage decreased (-0.09%) to 98.58% when pulling f5adfd3 on adhikasp:expand-star-import into d756487 on myint:master.

myint · 2017-06-16T13:54:43Z

Thanks!

The Pyflakes bugs were mentioned in #18.

myint · 2017-06-16T14:19:40Z

I put in a workaround (c07a90b) for the limitations mentioned in 1 and 2 above. It is conservative, but avoids those cases well enough to pass fuzz testing. We can remove them as Pyflakes improves.

jayvdb · 2017-06-17T12:41:46Z

Has a pyflakes bug been created about limitation "2" mentioned above?

adhikasp · 2017-06-19T19:09:06Z

@jayvdb yes it is PyCQA/pyflakes#280

adhikasp force-pushed the expand-star-import branch from 57db1b6 to 0cf2a22 Compare June 15, 2017 18:16

adhikasp force-pushed the expand-star-import branch from 0cf2a22 to 9a2ceec Compare June 16, 2017 02:00

myint requested changes Jun 16, 2017

View reviewed changes

adhikasp force-pushed the expand-star-import branch from 9a2ceec to f5adfd3 Compare June 16, 2017 04:41

myint approved these changes Jun 16, 2017

View reviewed changes

myint merged commit ad7cc64 into PyCQA:master Jun 16, 2017

myint added a commit that referenced this pull request Jun 16, 2017

Workaround Pyflakes bugs

c07a90b

The Pyflakes bugs were mentioned in #18.

jayvdb mentioned this pull request Jun 17, 2017

Minimum pyflakes version is v1.1.0 #21

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Add option to expand single star import #18

Add option to expand single star import #18

adhikasp commented Jun 15, 2017

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adhikasp commented Jun 19, 2017

Add option to expand single star import #18

Add option to expand single star import #18

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