ValueError: too many values to unpack - Is it possible to ignore one value?

Question

The following line returns an error:

self.m, self.userCodeToUserNameList, self.itemsList, self.userToKeyHash, self.fileToKeyHash = readUserFileMatrixFromFile         


        

Answer 1

It's common to use _ to denote unneeded variables.

a, b, c, d, e, _ = my_func_that_gives_6_values()

This is also often used when iterating a certain number of times.

[random.random() for _ in range(10)]  # gives 10 random values

Python 3 also introduced the * for assignment, similar to how *args takes an arbitrary number of parameters. To ignore an arbitrary number of arguments, just assign them to *_:

a, b, c, d, e, *_ = my_func_that_gives_5_or_more_values()

This can be used at any point in your assignment; you can fetch the first and last values and ignore padding in the middle:

>>> a, b, c, *_, x, y, z = range(10)
>>> print(a, b, c, '...', x, y, z)
0 1 2 ... 7 8 9