[ Web Proxy ]
URL:
Viewing: https://raw.githubusercontent.com/We2one/Notes/master/python-basic-notes/python-days/Day_06.md [Back]  [Original]

# Day_06

### 

+  :  ''/""/''''''' 

+  : 
    +  = ''
    +  = "" 
    +  = """()"""
    
+  : 

+  : []

+  : [start, stop[, step]]

+  : 
    + "+" : 
    + "*" : 
    
+ 
    +  = ""
    +  = str() ( int ,float, bool)

+ 
    + 
        
         | 
        :---: | :---:
        **.find()** |  -1
        .rfind() |  -1
        **.index()** | 
        .rindex() | 
        **.count()** | 
        **.endswith(suffix[, start[, end]])** |  TrueFalsestart end (Python)
        **.startswith(prefix[, start[, end]])** |  TrueFalsestart end (Python)
        
    + 
    
         | 
        :---: | :---:
        .partition() |     (str )
        .splitlines() |  () 
        **.split()** | ""maxsplit:  maxsplit  (maxsplit 1 )
        
        ```
          >>> str = "124\n441"
          >>> str.splitlines()
          ['124', '441']
          >>> str.partition("\n")
          ('124', '\n', '441')
          >>> str.split("4")
          ['12', '\n', '', '1']
          ```
   
    +  
    
          | 
        :---: | :---:
        **.replace()** | 
        .translate() |  from string import maketrans
        
    + 
    
         | 
        :---: | :---:
        **.center(width, fillchar)** |  
        .ljust(width, fillchar) | 
        .rjust(width, fillchar) | 
        .zfill(width) |  0 
        **.format(value, format_spec)** |  {}  :  %  format()  {}  format() 
        **.strip(chars)** |    (chars : )
        .rstrip(chars) |  (chars : )
        .lstrip(chars) |  (chars : )
        
    + 
        + format() 
            ```
          # 
          >>> ": {}, : {}:{}".format(19, "", "")
          ': 19, : :'
          # 
          >>> print(": {2}, : {1}:{0}".format("","", 19))
          : 19, : :
          #   
          >>> ": {age}, : {gender}:{name}".format(name="",gender="", age=19)
          ': 19, : :'
          # 
          >>> info = {"name": "", "age": 18}
          >>> ":{name},:{age}".format(**info)
          ':,:18'
          ```
            +  
                +  : :[][][]
                    + ":" :  ()
                        ```
                      >>> print("{:0>10}".format(""))
                      00000000
                      ```
            + 
                + :.2f  : 
                    ```
                  >>> print("{:.2f}".format(2))
                  2.00
                  ```
                + :b    : 
                    ```
                  >>> print("{:b}".format(2))
                  10  
                  >>> print("{:0>10.2f}".format(16))
                  0000016.00
                  ```
                + :o    : 
                    ```
                  >>> print("{:o}".format(16))
                  20
                  ```
                + :x    : 
                    ```
                  >>> print("{:x}".format(16))
                  10
                  ```
             
        +  --> 
            
             | 
            :---: | :---:
            %% | 
            %s | 
            %f | 
            %d/i |  ()
        
        +  --> f-string
            +  : f"{}"
            +  {} 
                ```
              >>> f"{2*8}"
              '16'
              ```
            + // /^
            + f"{:.2f}"
                ```
              >>> f"{13:.2f}"
              '13.00'
              ```
            + f"{:d}"
                ```
              >>> f"{13:b}"
              '1101'
              ```
            + f"{:o}"
                ```
              >>> f"{13:o}"
              '15'
              ```
            + f"{:x}"  
                ```
              >>> f"{13:x}"
              'd'
              ```
            
    + 
    
         | 
        :---: | :---:
        **.upper()** | 
        **.lower()** |  
        .swapcase() |  str
        **.title()** |   ****
        .capitalize() | 
        .expandtabs() |  tab  (\t)  (\t  8 )
        .casefold() |  **** 
        
    + 
        
         | 
        :---: | :---:
        .isalnum() | str  True False
        .isalpha() |  True False
        .isdigit() |  True False ( )
        .isupper() | () 
        .islower() | () 
        .istitle() |  True  False
        .isspace() |  True  False
        .endswith(suffix[, start[, end]]) |  TrueFalsestart end (Python)
        .startswith(prefix[, start[, end]]) |  TrueFalsestart end (Python)
        **.split()** | ""maxsplit:  maxsplit  (maxsplit 1 )

+ 
    
    + encode() :  "utf-8" str -> byte
        + str.encode(encoding="utf-8", errors='strict')
            + encoding:  "utf-8" utf-8gb2312cp936gbk
            + errors:    "strict" UnicodeEncodeError 'ignore''replace''xmlcharrefreplace'  codecs.register_error() 
    + decode() :  encoding  byte -> str
        + str.decode(encoding="utf-8", errors='strict')
            + encoding:  "utf-8" utf-8gb2312cp936gbk
            + errors:    "strict" UnicodeEncodeError 'ignore''replace''xmlcharrefreplace'  codecs.register_error() 

+  ()

     | 
    :---: | :---:
    \\ |   (\) 
    \' |   (')
    \" |   (")
    \n | 
    \t |  (tab)  8 
    \newline |  ()
    \other | 
    
    + repr()  ( n  '\',   '\'   n+1  '\',  repr()   n+1  '\'  2n  '\', print()    n/2  '\')
        ```
      >>> '\\\'
      '\\\\'
      >>> repr('\\\')
      "'\\\\\\\\'"
      >>> print('\\\')
      \\
      ```
      
      ```python
      str = input("  '\\   : ")
      str_count = str.count('\\')
      while str_count % 2 != 0:
          str_count += 1
      else:
          print(f'  \\  {str_count}')
          print(f"repr()  \\  {str_count*2}")
          print(f'print()   \\  {str_count//2}')
        ```
    
+ 
    +  r  R ()

Web Proxy Viewer  |  New URL  |  Original Page