"Python CookBook2" chapter I text-converting between one character && character and character value at a time

Text-Summary:

1. What is Text
   The string type in Python is an immutable type.
   Text, a matrix of characters, every single text can be indented and organized quickly.
   
   
2. Basic Text manipulation
   ① parse the data and put the data into the structure inside the program;
   ② the data in some way into another similar form, the data itself has changed;
   ③ to generate new data
   
   

process one character at a time:

• Task
  The string is processed with one character at a time.
  
  
• Solution Solutions
  You can create a list of subkeys that are characters of a string.
  The code is as follows:
  

  >>> thelist = List ('thestring')>>>thelist['T','h','e','s','T','R','I','N','g']>>> forCharinchthelist:PrintChar thestring>>> Map (LambdaX:x*3, Thelist) ['TTT','HHH','Eee','SSS','TTT','RRR','III','nnn','GGG']

Conversion between character and character values

• Task
  Convert a character to the corresponding Ascⅱ (ISO) or Unicode code, or to the contrary.
  
  
• Solution Solutions
  Built-in Functions Ord and CHR:
  

  >>> Ord ('a')97>>> chr'a  '

  
  If you want to convert a string into a list of values that contain individual characters, you might want to use the built-in map and ORD functions at the same time:

  Print map (ord,'python') [112, 121, 116, 104, 111, 110]

  
  If you want to create a string from a list that contains a character value, you can use the '. Join, map, and CHR

  Print ". Join (Map (Chr,range (97,100))) ABC

Experience:

1. Programming skills more reference to others, will become their own

2. The more basic the more you should remember and consolidate

3. It is said that the system business 80% is the processing of characters, so carefully study it

4. Do not accumulate kuibu to thousands of miles