How to break very long code lines in Python?

Question

How do I make my python code prettier by shortening each row? For example: I have a really long if statement that I would like to make shorter => split it's length on to a couple of rows:

if (imgA.shape[0] != imgB.shape[0]) and (imgA.shape[1] != imgB.shape[1]) and (imgA.shape[2] != imgB.shape[2]):

I would like to have something like this:

    if (imgA.shape[0] != imgB.shape[0]) and 
      (imgA.shape[1] != imgB.shape[1]) and
      (imgA.shape[2] != imgB.shape[2]):

But I get a syntax error. Anyone?

Jack Bashford · Answer 1 · 2019-09-18T00:08:42.653

4

Just compare the arrays themselves?

if imgA.shape != imgB.shape:

Or if the rest of the elements are important:

if imgA.shape[0:2] != imgB.shape[0:2]:

edited Sep 18 '19 at 00:08

answered Sep 18 '19 at 00:07

Jack Bashford

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ok, apparently a bad example. But how would you split this across mutliple lines? – Paul Erlenmeyer Sep 18 '19 at 00:08

Derek Eden · Accepted Answer · 2019-09-18T00:11:46.213

3

you can put it in brackets:

if ((imgA.shape[0] != imgB.shape[0]) and 
    (imgA.shape[1] != imgB.shape[1]) and 
    (imgA.shape[2] != imgB.shape[2])):
    #do stuff

edited Sep 18 '19 at 00:11

answered Sep 18 '19 at 00:09

Derek Eden

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This worked. Thanks! – Paul Erlenmeyer Sep 18 '19 at 00:11

score 2 · Answer 3 · answered Sep 18 '19 at 00:11

2

if (
    (imgA.shape[0] != imgB.shape[0]) and 
    (imgA.shape[1] != imgB.shape[1]) and
    (imgA.shape[2] != imgB.shape[2])
):
    #do something

I usually rely on parentheses around arguments for breaking lines. This passes syntax in a Jupyter notebook.

answered Sep 18 '19 at 00:11

Kermit

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Although I don't like to use middle of nowhere indentation and I feel like the more segmented the code is more easily understood, the @Derek_Eden answer is probably more black-correct. – Kermit Sep 18 '19 at 00:14

Farstride · Answer 4 · 2019-09-18T00:17:20.327

Not an exact answer, but a good idea would be to assign variable names to each of these:

check_shape_0 = imgA.shape[0] != imgB.shape[0]
check_shape_1 = imgA.shape[1] != imgB.shape[1]
check_shape_2 = imgA.shape[2] != imgB.shape[2]

if (check_shape_0) and (check_shape_1) and (check_shape_2):
    #Do something

The renamed booleans would be more clear to future code readers on what's going on in your if statements.

With well picked variable name for booleans, if statements can be read almost like English, which makes the code very comfortable to read through.

And the shorter names makes your if statement smaller.

score 1 · Answer 5 · answered Sep 18 '19 at 00:08

1

You can use \ to break the same statement into multiple lines:

if (imgA.shape[0] != imgB.shape[0]) and \
    (imgA.shape[1] != imgB.shape[1]) and \
        (imgA.shape[2] != imgB.shape[2]):

answered Sep 18 '19 at 00:08

Gabriel Cappelli

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Nice this worked. Thanks! – Paul Erlenmeyer Sep 18 '19 at 00:10
Happy to help. :) – Gabriel Cappelli Sep 18 '19 at 00:10

How to break very long code lines in Python?

5 Answers5