The N-way summary of the Python string concatenation _python

Python has a lot of string concatenation, writing code today, and by the way, summing up:

The original string connection method: Str1 + str2
Python new string concatenation syntax: STR1, STR2
Strange string Way: str1 str2
% connection string: ' name:%s; Sex: '% (' tom ', ' Male ')
String List connection: Str.join (some_list)

First of all, presumably as long as people with programming experience, it is estimated that the direct use of "+" to connect two strings:

' Jim ' + ' Green ' = ' jimgreen '

The second is special, if two strings are separated by commas, the two strings will be concatenated, but there is one more space between the strings:

' Jim ', ' green ' = ' Jim Green '

The third is also unique to Python, as long as you put two strings together, there is a gap in the middle or no blank: two strings are automatically connected to a string:

' Jim ' Green ' = ' jimgreen '
' Jim ' Green ' = ' jimgreen '

The fourth kind of function is quite powerful, borrowed from the C language function of printf, if you have the base of C language, see the document to know. In this way a string and a set of variables are concatenated with the symbol "%", and special tags in the string are automatically replaced with the variables in the right variable group:

'%s '% (' Jim ', ' green ') = ' jim, green '

The fifth kind of technique is the use of string function join. This function takes a list and then joins each element of the list in a string:

Var_list = [' Tom ', ' David ', ' John ']
A = ' ### '
A.join (var_list) = ' tom## #david # # #john '

In fact, Python also has a string concatenation method, but not much, is string multiplication, such as:

A = ' abc '
A * 3 = ' abcabcabc '