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pythonlist-comprehension

How can I get around declaring an unused variable in a list comprehension?


If I have a list comprehension (for example) like this:

['' for x in myList]

Effectively making a new list that has an empty string for every element in a list, I never use the x. Is there a cleaner way of writing this so I don't have to declare the unused x variable?


Solution

  • _ is a standard placeholder name for ignored members in a for-loop and tuple assignment, e.g.

    ['' for _ in myList]
    
    [a+d for a, _, _, d, _ in fiveTuples]
    

    BTW your list could be written without list comprehension (assuming you want to make a list of immutable members like strings, integers etc.).

    [''] * len(myList)