Python - Repeating Code Using Loops(while loop, if/else, list(remove method))

Practical Programming
An Introduction to Computer Science
Using Python 3
(Pragmatic Programmers)
(Pragmatic Bookshelf)
Paul Gries (著) Jennifer Campbell (著)
Jason Montojo (著) Lynn Beighley (編集)

開発環境

• OS X Mavericks - Apple(OS)
• Emacs (CUI)、BBEdit - Bare Bones Software, Inc. (GUI) (Text Editor)
• Python 3.4 (プログラミング言語)

Practical Programming: An Introduction to Computer Science Using Python 3 (Pragmatic Programmers) (Paul Gries (著)、Jennifer Campbell (著)、Jason Montojo (著)、Lynn Beighley (編集)、Pragmatic Bookshelf)のChapter 9(Repeating Code Using Loops)、9.10(Exercises) 12.を解いてみる。

9.10(Exercises) 12.

コード(BBEdit)

sample12.py

#!/usr/bin/env python3
#-*- coding: utf-8 -*-

def remove_neg(num_list):
    """ (list of number) -> NontType

    Remove the negative numbers from the list num_list

    >>> numbers = [-5, 1, -3, 2]
    >>> remove_neg(numbers)
    >>> numbers
    [1, 2]
    >>> numbers = [-1, -3]
    >>> remove_neg(numbers)
    >>> numbers
    []
    """
    i = 0
    while i < len(num_list):
        if num_list[i] < 0:
            num_list.remove(num_list[i])
        else:
            i += 1

if __name__ == '__main__':
    import doctest
    doctest.testmod()

入出力結果(Terminal, IPython)

$ ./sample12.py -v
Trying:
    numbers = [-5, 1, -3, 2]
Expecting nothing
ok
Trying:
    remove_neg(numbers)
Expecting nothing
ok
Trying:
    numbers
Expecting:
    [1, 2]
ok
Trying:
    numbers = [-1, -3]
Expecting nothing
ok
Trying:
    remove_neg(numbers)
Expecting nothing
ok
Trying:
    numbers
Expecting:
    []
ok
1 items had no tests:
    __main__
1 items passed all tests:
   6 tests in __main__.remove_neg
6 tests in 2 items.
6 passed and 0 failed.
Test passed.
$