Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
1.1k views
in Technique[技术] by (71.8m points)

function - Difference between returns and printing in python?


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

The Point

return is not a function. It is a control flow construct (like if else constructs). It is what lets you "take data with you between function calls".

Break down

  • print: gives the value to the user as an output string. print(3) would give a string '3' to the screen for the user to view. The program would lose the value.

  • return: gives the value to the program. Callers of the function then have the actual data and data type (bool, int, etc...) return 3 would have the value 3 put in place of where the function was called.

Example Time

def ret():
    return 3

def pri():
    print(3)

4 + ret() # ret() is replaced with the number 3 when the function ret returns
# >>> 7
4 + pri() # pri() prints 3 and implicitly returns None which can't be added
# >>> 3
# >>> TypeError cannot add int and NoneType

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

1.4m articles

1.4m replys

5 comments

57.0k users

...