Getting started with python,

Getting started with python,

Based on the file operations in the interactive window (the file name is user_list.cfg ):

>>> Print (open ('user _ list. cfg ', 'R'). read ())
User1: password1
User2: password2

>>> Print (open ('user _ list. cfg ', 'R '). readlines () [0]. split (':') [0]. strip ())
User1
>>> Print (open ('user _ list. cfg ', 'R '). readlines () [0]. split (':') [1]. strip ())
Password1
>>> Print (open ('user _ list. cfg ', 'R '). readlines () [1]. split (':') [0]. strip ())
User2
>>> Print (open ('user _ list. cfg ', 'R '). readlines () [1]. split (':') [1]. strip ())
Password2

Where:

Readlines () indicates reading the entire file and forming a list;

Readline () indicates reading a row at a time;

Read () indicates reading the entire file;

Split () indicates that strings are separated;

Strip () indicates removing spaces and line breaks at the beginning and end of a string;

 

Readlines () method:

>>> Print (open ('user _ list. cfg ', 'R'). readlines ())
['User1: password1 \ n', 'user2: password2 \ n']

We can see that the above method can read the entire file to form a list, including the special characters at the end of the line;

 

Read () method:

>>> Print (open ('user _ list. cfg ', 'R'). read () [1])
S
>>> Print (open ('user _ list. cfg ', 'R'). read () [0])
U
>>> Print (open ('user _ list. cfg ', 'R'). read () [2])
E
>>> Print (open ('user _ list. cfg ', 'R'). read () [3])
R
>>> Print (open ('user _ list. cfg ', 'R'). read () [4])
1

As shown in the preceding figure, the corresponding characters are extracted;

 

Readline () method:

>>> Print (open ('user _ list. cfg ', 'R'). readline (5 ))
User1

As shown above, the first five characters can be taken out;