Single line for loop

Question

Can someone help me rewrite this single line loop to a multiple lines for loop in python? I am trying to understand how it is formatted.

y = {element: r for element in variables(e)}

What do you need help with exactly? Create an empty dictionary and add one item in each iteration of the loop. — mkrieger1, Oct 30 '20 at 22:55
Dictionary comprehensions **are not single line for-loops**. Do not think of them as such. — juanpa.arrivillaga, Oct 30 '20 at 22:57
@juanpa.arrivillaga If the Python designers didn't want people to think of them like that, they shouldn't have used such similar syntax. :) — Barmar, Oct 30 '20 at 22:59
The title of the linked duplicate mentions list comprehensions, but the accepted answer includes dictionary comprehensions, and they are the same fundamental thing — juanpa.arrivillaga, Oct 30 '20 at 22:59
@Barmar perhaps, but the language maintainers are big on re-using keywords whenever possible. — juanpa.arrivillaga, Oct 30 '20 at 23:01
[Python List Comprehensions: Explained Visually](https://treyhunner.com/2015/12/python-list-comprehensions-now-in-color/) — Timus, Oct 30 '20 at 23:04
A better target: [What is this python expression containing curly braces and a for in loop?](https://stackoverflow.com/q/31846592/7851470) — Georgy, Oct 30 '20 at 23:05

score 2 · Accepted Answer · answered Oct 30 '20 at 22:57

2

The dictionary comprehension is equivalent to this loop:

y = {}
for element in variables(e):
    y[element] = r

answered Oct 30 '20 at 22:57

Barmar

score 0 · Answer 2 · answered Oct 30 '20 at 22:58

0

This is called a dict comprehension in python.

This syntax builds a dictionary by taking each element in the list variables(e) and associating it with the value r.

answered Oct 30 '20 at 22:58

Tordek

2 Answers2