python - 在python中将具有大变量名的代码分成两行

Question

我想将python代码分成两行，我的代码类似于：

if long_named_three_d_array[first_dimension][second_dimension][third_dimension] == somevalue:
    //dosomething

如果条件超过两行，我想在上面拆分。

请帮忙。谢谢。

Answer 1

在 Python 中，LHS 可以用括号括起来。

>>> a = {}
>>> a[1] = {}
>>> a[1][2] = {}
>>> (a[1][2]
... [3]) = ''
>>> a
{1: {2: {3: ''}}}
>>> (b) = 2
>>> b
2

这意味着您可以将您的行写为

if (long_named_three_d_array[first_dimension] 
    [second_dimension]
    [third_dimension] ) == somevalue:
# Rest of code here, obviously properly indented in for the if.

Answer 2

您可以使用换行符继续字符\.

if long_named_three_d_array[first_dimension] \
    [second_dimension]\
    [third_dimension] == somevalue:
# Rest of code here, obviously properly indented in for the if.

Answer 3

一种方法是使用临时变量：

tmp = long_named_three_d_array[first_dimension][second_dimension][third_dimension] 
if tmp == somevalue:
    //dosomething

如果可能的话，虽然更短但描述性的变量标识符将是一个更好的选择。