Three methods of Python string connection and their efficiency and application scenarios
The Python string connection method, generally has the following three kinds: Method 1: Directly through the plus (+) operator connection website=& 39;python& 39;+& 39;tab& 39;+& 39; com& 39; Method 2
The Python string connection method, generally has the following three kinds:
Method 1: Connect directly via the plus (+) operator
1
Website = ' python ' + ' tab ' + '. com '
Method 2:join Method
1
2
Liststr = [' Python ', ' tab ', '. com ']
Website = ". Join (LISTSTR)
Method 3: Replace
1
Website = '%s%s%s '% (' python ', ' tab ', '. com ')
Let's take a look at the difference between the three ways.
Method 1, simple and straightforward to use, but many online people say this method is inefficient
The reason why Python uses + for string connections is inefficient because the strings in Python are immutable types, a new string is generated when using + to concatenate two strings, and a new string is required to re-request the memory, when the string of successive additions is many (a+b+c+d+ e+f+ ...) , inefficiency is inevitable.
Method 2 uses a slightly more complex, but high-efficiency connection to multiple characters, with only one memory request. And if the character of the list is connected, this method must be the preferred
Method 3: String formatting, this method is very common, I also recommend the use of this method
Python Training Knowledge Summary Series-chapter II Python data Structure Part II, string concatenation