数据类型内置方法

数字类型内置方法

整型

• 1.用途：年龄、身份证号码、手机号。。。
• 2.定义方式：

age1 = 18age2 = int(18)print(age1)print(id(age1))print(type(age1))print(type(age2))

181723559936
    
     
    

• 3.常用操作和内置方法：+ - * / // ** % ；无内置方法
• 4.存一个值or多个值：一个值
• 5.有序or无序（有索引为有序，无索引为无序）：根本没有有序或无序的说法
• 6.可变or不可变：不可变

#不可变类型：值变则ID变age = 18print(id(age))age += 1print(id(age))

17235599361723559968

#可变类型：值变ID则不变list1 = ['name','height','weight']print(list1)print(id(list1))list1[1] = 185print(list1)print(id(list1))

['name', 'height', 'weight']1701728445128['name', 185, 'weight']1701728445128

浮点型

• 1.用途：身高、体重、薪水、存款
• 2.定义方式：

salary1 = 1.5salary2 = float(1.5)print((salary1))print(id(salary1))print(type(salary1))print(type(salary2))

1.51701727543560
    
     
    

• 3.常用操作和内置方法：+ - * / ** // % :无内置方法
• 4.存一个值or多个值： 一个值
• 5.有序or无序：根本没有有序无序一说
• 6.可变or不可变：不可变

字符串类型内置方法

• 1.用途：名字、单个爱好
• 2.定义方式：

name1 = 'william'name2 = "william"name3 = '''william1william2'''name4 = """william3william4"""print(type(name1))print(type(name4))

• 3.常用操作和内置方法：
  1.优先掌握
  *1.按索引取值

my_info_list = ['name','height', 'weight','hobby',['reading','running']]my_info = "name height weight hobby ['reading','running']"print(my_info_list[2])print(my_info[2])print(my_info_list[4])print(my_info[4])print(my_info[5])

weightm['reading', 'running'] h

***2.切片（顾头不顾尾），步长的正负控制行进的方向，左行进还是右行进。

my_info = "name height weight hobby ['reading','running']"print(my_info[:])print(my_info[0:6])print(my_info[0:8:2])print(my_info[-1:-4:-1])print(my_info[-4:-1])print(my_info[-4:])

name height weight hobby ['reading','running']name hnm e]'gng'ng']

***3.长度len

my_info = "name height weight hobby ['reading','running']"print(len(my_info))

46

***4.成员运算 in   not in

my_info = "name height weight hobby ['reading','running']"print('height' in my_info)print('hobbies'in my_info)

TrueFalse

***5.移除空白strip，默认为空格

test = '  a abc   a'print(test.strip())print(test.strip('a'))

a abc   a  a abc

***6.切分split

my_info = "name height weight hobby ['reading','running']"print(my_info.split())print(my_info.split(' ',2))print(my_info.split('i'))

['name', 'height', 'weight', 'hobby', "['reading','running']"]['name', 'height', "weight hobby ['reading','running']"]['name he', 'ght we', "ght hobby ['read", "ng','runn", "ng']"]

***7.循环

my_info = "name height weight hobby ['reading','running']"for i in my_info :    print(i,end=' ')

n a m e   h e i g h t   w e i g h t   h o b b y   [ ' r e a d i n g ' , ' r u n n i n g ' ]

2.需要掌握

*1.lstrip & rstrip

test = '   a  abc  a'print(test.lstrip())print(test.lstrip('a'))print(test.rstrip('a'))

a  abc  a   a  abc  a   a  abc

***2.lower & upper

my_info = "Name Height Weight hobby ['reading','running']"print(my_info.lower())print(my_info.upper())

name height weight hobby ['reading','running']NAME HEIGHT WEIGHT HOBBY ['READING','RUNNING']

***3.startswith & endswith

my_info = "name height weight hobby ['reading','running']"print(my_info.startswith('name'))print(my_info.startswith('he'))print(my_info.endswith('running'))

TrueFalseFalse

***4.rsplit

my_info = "name height weight hobby ['reading','running']"print(my_info.rsplit(' '))print(my_info.rsplit(' ',2))

['name', 'height', 'weight', 'hobby', "['reading','running']"]['name height weight', 'hobby', "['reading','running']"]

***5.join

my_info = "name height weight hobby ['reading','running']"my_info_split = my_info.split()print(my_info)print(my_info_split)print(''.join(my_info_split))print('.'.join(my_info_split))

name height weight hobby ['reading','running']['name', 'height', 'weight', 'hobby', "['reading','running']"]nameheightweighthobby['reading','running']name.height.weight.hobby.['reading','running']

***6.replace

my_info = "name height weight hobby ['reading','running']"print(my_info.replace('name','william').replace('weight','150'))

william height 150 hobby ['reading','running']

***7.isdigit

print('10dsf'.isdigit())print('10'.isdigit())

FalseTrue

**3.了解

# find \ rfind \ index \ rindex \ counthis_info = 'Name 1 WHEIGHT reading running reading 1 height'print(his_info.find('1'))  print(his_info.find('18'))  #记住不是False，而是-1print(his_info.rfind('1'))print(his_info.rfind('z'))  #记住不是False，而是-1

5-139-1

his_info = 'Name 1 WHEIGHT reading running reading 1 height'print(his_info.index('WHEIGHT'))#print(his_info.index('18'))  #会报错

7

his_info = 'Name 1 WHEIGHT reading running reading 1 height'print(his_info.count('reading'))

2

# center \ ljust \ rjust \ zfillprint('SS'.center(20,'*'))print('SS'.center(20,'+'))print('SS'.ljust(20,'*'))print('SS'.rjust(20,'+'))print('SS'.zfill(20))

*********SS*********+++++++++SS+++++++++SS******************++++++++++++++++++SS000000000000000000SS

# expandtabsprint('\tTom'.expandtabs(4))

Tom

#capitalize \ swapcase \ titleprint('tom and jerry'.capitalize())print('Tom and Jerry'.swapcase())print('tom and jerry'.title())

Tom and jerrytOM AND jERRYTom And Jerry

# is系列print('tom'.isdigit())print('tom'.isalpha())print('10'.isalpha())

FalseTrueFalse

• 4.存一个值or多个值：一个值
• 5.有序or无序：有序
• 6.可变or不可变：不可变

name = 'William'print(name)print(id(name))name += '2'print(name)print(id(name))

William1701731277152William21701731197360