From 8b39a2e86e1999f77e75c1ff3afce73c11311e10 Mon Sep 17 00:00:00 2001 From: David Rotermund <54365609+davrot@users.noreply.github.com> Date: Sat, 30 Dec 2023 19:58:23 +0100 Subject: [PATCH] Create README.md Signed-off-by: David Rotermund <54365609+davrot@users.noreply.github.com> --- python_basics/list_comprehensions​/README.md | 35 +++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 python_basics/list_comprehensions​/README.md diff --git a/python_basics/list_comprehensions​/README.md b/python_basics/list_comprehensions​/README.md new file mode 100644 index 0000000..3f62e0e --- /dev/null +++ b/python_basics/list_comprehensions​/README.md @@ -0,0 +1,35 @@ +# list-comprehensions​ +{:.no_toc} + + + +## Top + +Questions to [David Rotermund](mailto:davrot@uni-bremen.de) + + +## [List Comprehension](https://docs.python.org/3/tutorial/datastructures.html#list-comprehensions) + + +> List comprehensions provide a concise way to create lists. Common applications are to make new lists where each element is the result of some operations applied to each member of another sequence or iterable, or to create a subsequence of those elements that satisfy a certain condition. + +> For example, assume we want to create a list of squares + +```python + squares = [x**2 for x in range(10)] +``` + +> **A list comprehension consists of brackets containing an expression followed by a for clause, then zero or more for or if clauses. The result will be a new list resulting from evaluating the expression in the context of the for and if clauses which follow it.** + +```python +a = [(x, y) for x in [1, 2, 3] for y in [3, 1, 4] if x != y] +print(a) # -> [(1, 3), (1, 4), (2, 3), (2, 1), (2, 4), (3, 1), (3, 4)] +``` + + +### [Nested List Comprehensions](https://docs.python.org/3/tutorial/datastructures.html#list-comprehensions) + +> The initial expression in a list comprehension can be any arbitrary expression, including another list comprehension.