Which loop is nested inside the another ?

Question

1.00/5 (1 vote)

See more:

Python

[j for i in x for j in range(len(x)) if i == x[j]]

that is list comprehension the question is: is the loop ( for i in x) nested in the loop (for j in range(len(x)) or the converse?

What I have tried:

the ............................................loops

Posted 11-Jul-20 16:34pm

Ahmad Qassym

Updated 11-Jul-20 23:33pm

Richard MacCutchan

v2

Add a Solution

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

OriginalGriff · Accepted Answer · 2020-07-11T19:52:00

Solution 1

Apart for not compiling as is, so the code sample you show won't work, give it a try: replace the "if" with a print statement and show the values of i and j.
Whichever goes up first is the inner loop.

Posted 11-Jul-20 19:52pm

OriginalGriff

Comments

Richard MacCutchan 12-Jul-20 5:31am

Runs fine in my Python.

Richard MacCutchan · Accepted Answer · 2020-07-11T23:33:00

Using a simple example we get the equivalent shown here:

Python

    x = [ 2, 3, 4, 7, 11 ]
    z = [j for i in x for j in range(len(x)) if i == x[j]]
    print(z)

# which is the same as
    zzz = []
    for i in x:
        for j in range(len(x)):
            if i == x[j]:
                zzz.append(j)
    print(zzz)

And the output is:

[0, 1, 2, 3, 4]
[0, 1, 2, 3, 4]