python-字符串数据类型内置方法

name = 'rayn'
print(type(name))

<class 'str'>

nums = 123
print(type(nums))
nums = str(123)
print(type(nums))

<class 'int'>
<class 'str'>

name = 'rayn handsome'
print(name[0])  ## 整向取值,取第一个索引值
print(name[-1])  ## 反向取值

r
e

name = 'rayn handsome'
print(name[0:5])  ## 正向取值,步长默认为1,索引范围是0-5:就是说取前四个字符
print(name[0:5:2]) ## 正向取值,步长为2,取前四个字符中的第一个和第三个
print(name[-4:])  ## 正向取值,步长为1,取后面四个字符
print(name[-1:-5:-1]) ## 反向取值,步长为1,取后面四个字符,且顺序是反的

rayn 
ry 
some
emos

name = 'rayn handsome'  ## 注意单引号里面的空格也是字符串
print(len(name))

13

name = 'rayn handsome'
print('rayn'in name)
print('nick'in name)
print('rayn'not in name)

True
False
False

name = '  rayn handsome '
print(name)
print(name.strip())

  rayn handsome 
rayn handsome

name = '  rayn handsome '
print(name.split())
print(name.split('h'))

['rayn', 'handsome']
['  rayn ', 'andsome ']

name = '  rayn handsome '
for i in name:
    print(i)

h
a
n
d
s
o
m
e

name = '  rayn handsome '
print(name.lstrip())
print(name.rstrip())

rayn handsome 
  rayn handsome

name = '  Rayn Handsome '
print(name.lower())
print(name.upper())

  rayn handsome 
  RAYN HANDSOME 

name = 'rayn handsome '
print(name.startswith('r'))
print(name.endswith('h'))

True
False

name = 'rayn handsome '
print(name.rsplit('s'))

['rayn hand', 'ome ']

lis = ['rayn','handsome','shuai']
print('='.join(lis))

rayn=handsome=shuai

name = 'rayn handsome '
print(name.replace('handsome','taishuai'))

rayn taishuai 

name = 'rayn handsome '
print(name.isdigit())

False

age = input('请输入年龄:')
if age.isdigit():
    age = int(age)
else:
    print('不知道年龄是数字吗?')

请输入年龄:喔喔
不知道年龄是数字吗?