Type of basic data base 1 python

1. int plastic
   • For calculating and comparing the digital
   • python3 not long, python2 have plastic surgery and long integer
2. Binary decimal conversion method
   • bin (10 decimal) == Binary
   • 0b (binary)
   • int ( "binary", 2) == decimal
3. In shaping the number is not 0 is boolean value will be true
4. Boolean value, True to 1 (int) Fslse is 0 (int)
5. As long as the string is not empty Ture, a space is Ture
6. str (True), str (False) are derived from a string
7. String
   • python, as long as a quoted string is ''. "." "" "" ""
   • String mainly used for data storage, a small amount of stored data
   • Each letter string or character element is referred to as
   • Index (subscript)

• From left to right, starting at zero. Find: String name [index] (the brackets [] mean the look similar) A [0] == mA [. 1] == EA [2] == EA [. 3] == T
  - from right to left , starting with -1. Find: String name [index] ** (in brackets [] to find the similar meaning) a = "meet" a [ -1] == ta [-2] == e a- [3] == ea [-4] m ==
  - when index not exceed the maximum index (zero-based) or minimum (from the right at -1)
• slice
  • a [0: 5], care regardless tail ,, a [starting position: not write (default to the last position)] ,,, a [not write (): Do not write (default to the last position)]
    • a[-5:-1],,,
    • Time is sliced ​​raw data itself
• Steps
  • Find decided to step direction a [:: step], step size value determines how much each step across, positive or negative decision to seek direction
    • a [start index (0 is not written by default): the end of the table (not included, the default is not written last value): positive step]
    • a [start index (the default is not written -1): at the end of the table (not included, the default is not written to the first value): negative step]
• String Methods
  • name = "sssd"
    
  • The number of characters that appear name.count ()
    • name.startswith( , , )
    • name.endswitch(，，)
    • name.upper()
    • name.lower()
    • name.strip () # Default off head and tail sides spaces, carriage returns, tabs. name.strip ( "stripped Content")
    • name.split ( "what division", cut a few (not default write full cut))
    • name.replace (to be for a. change the contents, replace the contents for a few (not default write full replacement))
    • String formatting, name = "{} {} year years old" .format ( "junke", 18)
    • String formatting, name = "{name} {age} year years old" .format ( "name =" junke ", gre = 18)
    • String formatting, name = "{0} 1} {year years old" .format ( "junke", 18), according to the following standard
  • Class is based
    - name.isdigit () string is not judged are whole numbers
    - name.isdecimal () judgment is not = decimal name "123"
    - name.isalnum () judgment is not alphanumeric Chinese
    - name.isalpha ( ) judgment is not a letter Chinese
    - name.isupper ()
    - name.islower ()
    • len (name), find the string length

1. for loop

   • name= "ekeke" 可迭代对象
     for i in name：
       print(i)
     print(i)
     #输出ekeke    e
     #相当于 i=name[0]...执行到最后，i = a[3] ==e
     
     for i in name:
         pass
     print(i)
     #输出内容  e
     #for循环中pass占位，无内容。但是循环依旧，循环到最后，i=name[3]
     
     
     for i in name:
         i = i+"ke"
     print(i)
     

2. Iterables

   • In addition to data type int python and the rest can be bool value iteration are iterables