如何在列表理解中执行以下操作?
test = [["abc", 1],["bca",2]]
result = []
for x in test:
if x[0] =='abc':
result.append(x)
else:
pass
result
Out[125]: [['abc', 1]]
尝试 1:
[x if (x[0] == 'abc') else pass for x in test]
File "<ipython-input-127-d0bbe1907880>", line 1
[x if (x[0] == 'abc') else pass for x in test]
^
SyntaxError: invalid syntax
尝试 2:
[x if (x[0] == 'abc') else None for x in test]
Out[126]: [['abc', 1], None]
尝试 3:
[x if (x[0] == 'abc') for x in test]
File "<ipython-input-122-a114a293661f>", line 1
[x if (x[0] == 'abc') for x in test]
^
SyntaxError: invalid syntax
最佳答案
if
需要放在最后,您不需要在列表理解中使用 pass
。仅当满足 if
条件时才会添加该项目,否则将忽略该元素,因此 pass
在列表理解语法中隐式实现。
[x for x in test if x[0] == 'abc']
为了完整起见,此语句的输出为:
[['abc', 1]]
关于python - 使用 else pass 的列表理解,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/33691552/