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Advanced Python: for more attractive code

Taeho Jeon on May 20, 2019

Tips and Tricks for Advanced Python Python is a high-level, interpreted, interactive and object-oriented scripting language. Python is...

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Daniel Tinsley • May 21 '19

I think it depends on how complicated the comprehension or the ternary expression is. If it's hard to comprehend, then a loop or an if...elif...else statement would be better, but if it's a simple statement, then a comprehension or ternary expression is just as good and is more Pythonic.

werlindo • May 20 '19

Thank you! Very helpful!!

Taeho Jeon • May 21 '19

WIth my pleasure~~~

Burdier • May 21 '19

I agree with you.

Maxime Moreau • May 21 '19

Hi, thanks for sharing :)

"else statement also be used after for loop, it is executed after for loop", but why it could be needed? Just put some code after the for loop do the job, nop?

Daniel Tinsley • May 21 '19

The 'else' is used if the loop completes successfully, so if the loop ends early, such as by using a 'break' statement, the 'else' won't run. It's just an easier way to run code if and only if the loop finishes successfully without needing to use a flag variable to detect whether the loop finishes.

With flag:

flag = True
for i in range(10):
    if i == 8:
        flag = False
if flag:
    print('Loop completed') # won't print, since flag is False

With 'else':

for i in range(10):
    if i == 8:
        break
else:
    print('Loop completed') # won't print since the loop ended early

In both cases, the text won't print, since the loop didn't complete. However, if the loops did complete, then the text would print.

Maxime Moreau • May 24 '19

Hi, well thank a ton! :)

Taeho Jeon • May 21 '19

Hi, you're welcome.

else: after for loop confirms the for loop is finished, not confirms the exit of the loop.

else: does not be executed when it is exited by 'break' statement.

Taeho Jeon • May 21 '19

Thanks for the feedback. I agree with you.

Juneau Lim • May 21 '19

Wow, I know only half of them. Thanks for the great tips!

Taeho Jeon • May 21 '19

You're welcome!