Imports are always moved to top of the file

[Tadaboody]

Running autopep8 on

"""Module docstring"""
a = 5
import random
import itertools

results in

import itertools
import random
"""module docstring"""
a = 5

Instead of

"""module docstring"""
import itertools
import random
a = 5

[Tadaboody]

@hhatto Imports are also moved above __future__ imports. This creates a syntax error.

[Hanaasagi]

@Tadaboody. emm, I meet the same problem. Maybe this patch can solve that imports are moved above from __future__ import

def get_module_imports_on_top_of_file(source, import_line_index):
    """return import or from keyword position

    example:
      > 0: import sys
        1: import os
        2:
        3: def function():
    """
    def is_string_literal(line):
        if line[0] in 'uUbB':
            line = line[1:]
        if line and line[0] in 'rR':
            line = line[1:]
        return line and (line[0] == '"' or line[0] == "'")

    def is_future_import(line):
        nodes = ast.parse(line)
        for node in nodes.body:
            if isinstance(node, ast.ImportFrom) and node.module == '__future__':
                return True
        return False

    allowed_try_keywords = ('try', 'except', 'else', 'finally')
    for cnt, line in enumerate(source):
        if not line.rstrip():
            continue
        elif line.startswith('#'):
            continue
        if line.startswith('import ') or line.startswith('from '):
            if cnt == import_line_index or is_future_import(line):
                continue
            return cnt
        elif pycodestyle.DUNDER_REGEX.match(line):
            continue
        elif any(line.startswith(kw) for kw in allowed_try_keywords):
            continue
        elif is_string_literal(line):
            return cnt
        else:
            return cnt
    return 0

It adapts to following situation

import math
a = 1
import collections
from __future__ import print_function
import functools

But it can't solve that

import collections
from __future__ import print_function
a = 1

Because, the above code will pass the check of pycodestyle. It only checks E402(Module level import not at top of file), but pyflakes contains additional check F404(from __future__ imports must occur at the beginning of the file)

By the way, I think PEP8 is just code style, not a lint. It considers that the problem is not caused by autopep8, actually it's not a tool to fix SyntaxError.

Reference Flake8Rules

[Tadaboody]

@Hanaasagi Will it fix the case of turning

from __future__ import print_function
print(3)
import functools
print(4)

into

import functools
from __future__ import print_function
print(3)
print(4)

Thus creating a syntax error by using autopep8?

[Hanaasagi]

I think so. autopep8 depends on pycodestyle, above code will report that

t.py:3:1: E402 module level import not at top of file

And this patch using ast module to check whether the target line contains a __future__ import. if has, it will insert to next suitable position.

[waspinator]

imports are also moved above sys.path.insert(), which breaks the import statement.

[hhatto]

It is resolved in this issue:

• Change the import statement that it does not moved above the module document by E402 (Thanks @Hanaasagi )
• Change the import statement that it does not moved above the from __future__ import XX by E402 ( Thanks @Hanaasagi )

[Hanaasagi]

I'd like to resolve the remianing issue.

[Hanaasagi]

#467