Python - Working with Text(built-in function(len), the length of the empty string)

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 4(Working with Text)、4.7(Exercises) 4.を解いてみる。

4.7(Exercises) 4.

コード(BBEdit)

sample8.py

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

def square(num):
    return num * num

if __name__ == '__main__':
    for num in range(10):
        print('square({0}) -> {1}'.format(num, square(num)))

入出力結果(Terminal, IPython)

$ ipython
Python 3.4.1 (default, May 21 2014, 01:39:38) 
Type "copyright", "credits" or "license" for more information.

IPython 2.1.0 -- An enhanced Interactive Python.
?         -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help      -> Python's own help system.
object?   -> Details about 'object', use 'object??' for extra details.

In [1]: len('')
Out[1]: 0

In [2]: len("")
Out[2]: 0

In [3]: s = ''

In [4]: len(s)
Out[4]: 0

In [5]: s = ""

In [6]: len(s)
Out[6]: 0

In [7]: s = """"""

In [8]: len(s)
Out[8]: 0

In [9]: s = ''''''

In [10]: len(s)
Out[10]: 0

In [11]: quit()
$