zip()#
The zip() function is used to take iterables as arguments, pack the corresponding elements from each object into tuples, and then return an object composed of these tuples.
>>> a = [1, 2, 3]
>>> b = [4, 5, 6]
>>> c = [4, 5, 6]
>>> zipped = zip(a, b, c)
>>> zipped
<zip object at 0x00000278786975C0>
>>> list(zipped)
[(1, 4, 4), (2, 5, 5), (3, 6, 6)]
One application of this is to iterate through multiple arrays simultaneously:
>>> for i, j, k in zip(a, b, c):
... print(i, j, k)
...
1 4 4
2 5 5
3 6 6
If the arrays are of unequal length, the shortest length will be used.
If you want to use the longest length, you can use another function called zip_longest(), but I won't go into detail here.
enumerate()#
The enumerate() function is used to combine a traversable data object (such as a list, tuple, or string) into an indexed sequence, while listing both the data and the index.
>>> seasons = ['Spring', 'Summer', 'Fall', 'Winter']
>>> list(enumerate(seasons))
[(0, 'Spring'), (1, 'Summer'), (2, 'Fall'), (3, 'Winter')]
This can also be used during iteration.
Notes#
When using these two functions, you need to import the itertools module, otherwise an error will occur.