Two examples of using join in Python are shared

Python uses two instances of join to share

a1 = {: , : , : , : = open(,,encoding= key ===  +

If you want to merge (list, tuple, dictionary, file, set or generator, etc. ) string is a sequence or iterable, the fastest way is to use the join() method

[python] view plain copy
>>> a = ["hello", "world"]  
>>> a  
['hello', 'world']  
>>> ' '.join(a)  
'hello world'  
>>> ','.join(a)  
'hello,world'  
>>> ''.join(a)  
'helloworld'

If you want to merge (list, tuple, dictionary, file, collection or generator, etc.) If the string is a sequence or iterable, the fastest way is to use the join() method

[python] view plain copy
>>> a = ["hello", "world"]  
>>> a  
['hello', 'world']  
>>> ' '.join(a)  
'hello world'  
>>> ','.join(a)  
'hello,world'  
>>> ''.join(a)  
'helloworld'

Usually when formatting strings, improper selection can cause serious problems to the application. Performance loss, when we use the plus (+) operator to concatenate a large number of strings, it is very inefficient, because the plus sign connection will cause memory copying and garbage collection operations. Each time the += operation is performed, a new string object is created. You're better off collecting all the string fragments first and then concatenating them.

Conclusion: When to use (+) and when to use join, you should decide which solution to use based on the characteristics of your application

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