Python基础四

# for i in range(0,10): # 结果是0-9，顾头不顾尾
#     print(i)
# for i in range(0,10,2): # 结果是0,2,4,6,8，步长为2
#     print(i)
# msg='hello world'
# for i in range(0,len(msg)):
#     print(msg[i])
# for i in range(len(msg)): # 0可以去掉
#     print(msg[i])
# for i in range(1,len(msg)): # 0不是开头时不可以去掉
#     print(msg[i])
# print('***qwer***'.strip('*')) # qwer
# print('***qwer***'.rstrip('*')) # ***qwer
# print('***qwer***'.lstrip('*')) # qwer***
# lower upper
# print('OBos'.lower()) # obos
# print('OBos'.upper()) # OBOS
# startswith endswith
# msg="qwer is LOL's basic operation"
# print(msg.startswith('qwer'))
# print(msg.startswith('q'))
# print(msg.endswith('SB'))
# print(msg.endswith('S'))

#  format
# print('my name is %s,my age is %s'%("lili",18))
# print('my name is {},my age is {}'.format('lili',18)) # 花括号
# print('my name is {name},my age is {age}'.format(age=18,name='lili'))
# print('{0}{1}{0}'.format('lili',18)) # lili18lili
# print('{0}{1}{0}'.format('lili',18,22)) # lili18lili

# mesg='root:a:d:0'
# l=mesg.split(':')
# print(l) # ['root', 'a', 'd', '0']
# # join 只有列表内的元素都是字符串类型，才能用join拼接
# print(':'.join(l)) # root:a:d:0

# replace
# info='A say he name is xm,A say he has a T'
# info=info.replace('A','xm')
# print(info) # xm say he name is xm,xm say he has a T
# info='A say he name is xm,A say he has a T'
# info=info.replace('A','xm',1)
# print(info) # xm say he name is xm,A say he has a T

# isdigit 判断字符串是不是数字
# age=input('>>:').strip()
# print(age.isdigit())
# age=int(age)
# print(age)
# age=input('>>:').strip()
# if age.isdigit():
#     print(age)
# else:
#     print('请输入纯数字')

# find rfind（相反） index rindex（相反） count 统计数量
# cmd='you are my apple'
# print(cmd.find('my')) # 8
# print(cmd.find('c')) # -1
# print(cmd.index('my')) # 8
# print(cmd.index('c')) # 报错
# print(cmd.count('y')) # 2

# center ljust rjust zfill 打印
# print('just do it'.center(40,'*')) # ***************just do it***************
# print('just do it'.ljust(40,'*')) # just do it******************************
# print('just do it'.rjust(40,'*')) # ******************************just do it
# print('just do it'.zfill(40)) # 000000000000000000000000000000just do it

# expandtabs
# print('hello	world') # hello    world
# print('just	do	it'.expandtabs(30)) # just                          do                            it

# capitalize title swapcase
# print('just do it'.capitalize()) # Just do it 首字母大写
# print('just do it'.title()) # Just Do It 每一个单词的首字母大写
# print('just do it'.swapcase()) # JUST DO IT 大小写反转

# 列表追加 append insert extend
# l=['lili','asdf','qwer','80000']
# l.append(4) # ***************
# print(l)
# l=['lili','asdf','qwer','80000']
# l.insert(0,'dear') # 把dear添加在索引0的前面
# print(l) # ['dear', 'lili', 'asdf', 'qwer', '80000']
# l=['lili','asdf','qwer','80000']
# l.extend('hello')
# print(l) # ['lili', 'asdf', 'qwer', '80000', 'h', 'e', 'l', 'l', 'o']

# 单纯删除 del remove 取走 pop 括号里不加东西，默认从末尾删除
# l=['lili','asdf','qwer','80000']
# del l[1]
# print(l) # ['lili', 'qwer', '80000']
# l=['lili','asdf','qwer','80000']
# l.remove('asdf')
# print(l) # ['lili', 'qwer', '80000']
# l=['lili','asdf','qwer','80000']
# l.pop(1)
# print(l) # ['lili', 'qwer', '80000']
# l=['lili','asdf','qwer','80000']
# cmd=l.pop(1)
# print(cmd) # asdf
# l=['lili','asdf','qwer','80000']
# l.pop(1)
# print(l.pop(0)) # lili
# print(l.pop(0)) # qwer
# print(l.pop(0)) # 80000

# 循环 item
# l=['lili','asdf','qwer','80000']
# for item in l:
#     print(item) # lili asdf qwer 80000

#  清空 clerr
# l=['lili','asdf','qwer','80000']
# l.clear()
# print(l) # []