In section 3.1.2 of the python documentation, its mentioned as below:

Two or more string literals (i.e. the ones enclosed between quotes) next to each other are automatically concatenated.
This feature is particularly useful when you want to break long strings:
This only works with two literals though, not with variables or expressions:

However, the concatination operation works on variables and expressions also.
Please find the below python code snippet and the output:

Python Code:
-------------
s1='Hello'
s2=' World '
s3=' How are you ? '
print(s1, s2, "\n", s3, "\n")
print('---------------------------')
print('Long time ' 'No see mate ')
print("Hope ", 'All is ' "good")
print('---------------------------')
print(s1, 'World'," !!")
print((s1+s2+s3)*2," there ?")


Output:
--------
Hello  World                                                                                                          
  How are you ?                                                                                                       
                                                                                                                      
---------------------------                                                                                           
Long time No see mate                                                                                                 
Hope  All is good                                                                                                     
---------------------------                                                                                           
Hello World  !!                                                                                                       
Hello World  How are you ? Hello World  How are you ?   there ?