如何比较列表中的空值

Question

I have an array of string and I want to know how to add a string if some of the values is empty. P. eg:

array=["1","3","","7"]

With the previous array I want to save a string value in the third position of the array (2 index) because it is empty. How can I probe it?

Code:

if array[2]== ?:

What should I write instead of "?"

Answer 1

An empty string is equivalent to False , so you can simply do:

if not array[2]:

Answer 2

You can do this quite nicely with a list comprehension in python:

array=["1","3","","7"]

new_array = [x if x!="" else "replaced" for x in array]
new_array

returns

['1', '3', 'replaced', '7']