python base (a) built-in type and method

python built-in types mainly includes seven major categories:

• digital
• sequence
• Mapping
• file
• class
• Examples

• Abnormal
  wherein the data type is the most common sequence

  sequence

  Built-in python sequence containing 7
  
• List (list): constituted by square brackets separated by commas items: [a, b, c]
  
• Tuple (tuple): tuple comma operator configured (not in brackets), the brackets must be empty tuple brackets, eg: (d,) ()
• String (str): single or double quotes written, eg: "abc", 'abc'
  
• unicode string (unicode): str with similar, but designated by u before use, eg: u "abc", u'abc '
  
• Byte array (bytearray): Use the built-bytearray () function to create an object Bytearray
• buffer objects (buffer): created by calling the built-in function buffer (). They do not support connections or repeat

• xrange objects (xrange): Use xrange () function created. They do not support sections, connections or repeat

  General Operation Sequence

  operating	result	Explanation
  x in s	True or False	Determine whether x is a member of s
  s + t	st	s and t are connected
  s * n , n * s	sequence	S new sequence consisting of a sequence of n
  s[i]	An element	An element access sequence s
  s[i:j]	Range of elements	S access to the range of elements in the sequence
  s[i:j:k]	Range of elements	S access sequence steps within a range of k elements
  only (a)	Numerical	Length sequence s
  min (s)	Numerical	Minimum sequence s
  max(s)	Numerical	The maximum value of the sequence s
  s.index(x)	Numerical	Access location index x occurring sequence s
  s.count(x)	Numerical	X s in the number of elements in the sequence of occurrence

Common methods string

> 1.str.capitalize() #返回字符串副本，第一个字母大写，其余小写
> 2.str.count(sub) #返回sub字符出现的次数
> 3.str.encode()/str.deconde() #编码/解码
> 4.str.find() #返回某元素第一次出现的索引
> 5.str.format() #格式化字符串
> 6.str.join(seq) #指定字符串连接
    eg：
    str = "-";
    seq = ("a", "b", "c"); 
    print str.join(seq);
    a-b-c
> 7.str.lower() #所有包含字符转化为小写
> 8.str.replace(old,new) #字符替换
> 9.str.split(' ') #通过指定字符串切片
>10.str.startswith(sub)/str.endwith(sub) #检查是否以sub开始/结束
>11.str.strip(sub) #移除字符串头尾指定的字符序列