Pythonic方式结合FOR循环和IF语句 [英] Pythonic way to combine FOR loop and IF statement

问题描述

 >>>我知道如何在循环和if语句中使用单独的行; a = [2,3,4,5,6,7,8,9,0] 
 ... xyz = [0,12,4,6,242,7,9] 
 ...在xyz中为x：
 ...如果x在a中：
 ... print（x）
 0,4,6,7,9 
  
 
 
我知道当语句很简单时，我可以使用列表理解来组合这些语句，如：/ b 
 
 
  print（[x for xyz if x in a]）
  
但是我找不到任何地方的一个很好的例子（复制和学习），演示一组复杂的命令（不仅仅是print x），这些命令在for循环还有一些if语句。一些我期望的样子：
  for x in xyz if x not in a：
 print（x。 ..）
  
这不是python应该工作的方式吗？
解决方案
您可以使用生成器表达式如下所示：
 
 $ $ $ $ $ $ $ $ $ $ $ $ $ $ x $ x $ x $ x $ x $ x $ x $ x $ x $ x 
 
 for x：
 print x 
  

I know how to use both for loops and if statements on separate lines, such as:

>>> a = [2,3,4,5,6,7,8,9,0]
... xyz = [0,12,4,6,242,7,9]
... for x in xyz:
...     if x in a:
...         print(x)
0,4,6,7,9

And I know I can use a list comprehension to combine these when the statements are simple, such as:

print([x for x in xyz if x in a])

But what I can't find is a good example anywhere (to copy and learn from) demonstrating a complex set of commands (not just "print x") that occur following a combination of a for loop and some if statements. Something that I would expect looks like:

for x in xyz if x not in a:
    print(x...)

Is this just not the way python is supposed to work?

解决方案

You can use generator expressions like this:

gen = (x for x in xyz if x not in a)

for x in gen:
    print x

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