ob-vaults/Phoenix/Python/Python List Comprehension.md
2024-09-12 17:54:01 +03:30

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status: #doc
Tags: : #python #programming
links:[[python]]
Date: 2023-05-04
___
# Python List Comprehension
syntax
```python
new_list = [expression for item in iterable if condition]
```
- expression : what to do to item from iterable for example if in list of `[1,2,3]` we have x as item if we do `x*2` the list we get is `[2,4,6]`
- item : for every iteration on iterable (list,string,...) we get one item so here we name it
- iterable (list,string,...)
- condition : an if statement that look at the item if it get true it send it to expression for handling and its optional
Here's an example that demonstrates how to use a list comprehension to create a new list of even numbers from an existing list:
```python
# create a list of numbers
numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
# use a list comprehension to create a new list of even numbers
even_numbers = [x for x in numbers if x % 2 == 0]
# print the new list
print(even_numbers)
```
---> output
```
[2, 4, 6, 8, 10]
```
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# References
https://www.programiz.com/python-programming/list-comprehension
https://peps.python.org/pep-0202/