2.3.3. Join Iterables#
2.3.3.1. join method: Turn an Iterable into a Python String#
If you want to turn an iterable into a string, use join()
.
In the code below, I join elements in the list fruits
using “, “.
fruits = ['apples', 'oranges', 'grapes']
fruits_str = ', '.join(fruits)
print(f"Today, I need to get some {fruits_str} in the grocery store")
Today, I need to get some apples, oranges, grapes in the grocery store
2.3.3.2. Zip: Associate Elements from Two Iterators based on the Order#
If you want to associate elements from two iterators based on the order, combine list
and zip
.
nums = [1, 2, 3, 4]
string = "abcd"
combinations = list(zip(nums, string))
combinations
[(1, 'a'), (2, 'b'), (3, 'c'), (4, 'd')]
2.3.3.3. Unzip a List of Iterables#
You can turn a list of iterables into 2 separate iterables using zip(*list)
.
comb = [(1, 'a'), (2, 'b'), (3, 'c'), (4, 'd')]
nums_2, chars_2 = zip(*comb)
nums_2
(1, 2, 3, 4)
2.3.3.4. Difference between list append and list extend#
If you want to add a list to another list, use the append
method. To add elements of a list to another list, use the extend
method.
# Add a list to a list
a = [1, 2, 3, 4]
a.append([5, 6])
a
[1, 2, 3, 4, [5, 6]]
a = [1, 2, 3, 4]
a.extend([5, 6])
a
[1, 2, 3, 4, 5, 6]