Is it possible to break a long line to multiple lines in Python

Just like C, you can break a long line into multiple short lines. But in Python, if I do this, there will be an indent error... Is it possible?

---

From PEP 8 - Style Guide for Python Code:

The preferred way of wrapping long lines is by using Python's implied line continuation inside parentheses, brackets and braces. If necessary, you can add an extra pair of parentheses around an expression, but sometimes using a backslash looks better. Make sure to indent the continued line appropriately.

Example of implicit line continuation:

a = some_function(
    '1' + '2' + '3' - '4')

On the topic of line-breaks around a binary operator, it goes on to say:-

For decades the recommended style was to break after binary operators. But this can hurt readability in two ways: the operators tend to get scattered across different columns on the screen, and each operator is moved away from its operand and onto the previous line.

In Python code, it is permissible to break before or after a binary operator, as long as the convention is consistent locally. For new code Knuth's style (line breaks before the operator) is suggested.

Example of explicit line continuation:

a = '1'   
    + '2' 
    + '3' 
    - '4'

---

There is more than one way to do it.

1). A long statement:

>>> def print_something():
         print 'This is a really long line,', 
               'but we can make it across multiple lines.'

2). Using parenthesis:

>>> def print_something():
        print ('Wow, this also works?',
               'I never knew!')

3). Using again:

>>> x = 10
>>> if x == 10 or x > 0 or 
       x < 100:
       print 'True'

Quoting PEP8:

The preferred way of wrapping long lines is by using Python's implied line continuation inside parentheses, brackets and braces. If necessary, you can add an extra pair of parentheses around an expression, but sometimes using a backslash looks better. Make sure to indent the continued line appropriately. The preferred place to break around a binary operator is after the operator, not before it.

---

If you want to assign a long str to variable, you can do it as below:

net_weights_pathname = (
    '/home/acgtyrant/BigDatas/'
    'model_configs/lenet_iter_10000.caffemodel')

Do not add any comma, or you will get a tuple which contains many strs!

链接地址: http://www.djcxy.com/p/6570.html

上一篇: 如何使Python脚本独立可执行文件在没有任何依赖的情况下运行？

下一篇: 是否有可能在Python中打破多行