day06 for循环 数字类型 字符串类型

for循环 

l=['a','b','c']
# print(len(l))
# i=0
# while i<len(l):
#     print(l[i])
#     i+=1

# l=['a','b','c']
# for item in l: #item='a'
#     print(item)

# dic={'x':111,'y':222,'z':333}
# for k in dic: #k='x'
#     print(k,dic[k])


#while循环 VS for循环
#1.
#while循环:称之为条件循环,循环的次数取决于条件何时为False
#for循环:称之为迭代循环,循环的次数取决于数据的包含的元素的个数

#2.
#for循环专门用来取值,在循环取值方面比while循环要强大,以后但凡
#遇到循环取值的场景,就应该用for循环

#  0   1    2
# l=['a','b','c']
# for i in range(3):
#     print(i,l[i])


# for+break
# names=['egon','kevin','alex','hulaoshi']
# for name in names:
#     if name == 'alex':break
#     print(name)



# for+continue
# names=['egon','kevin','alex','hulaoshi']
# for name in names:
#     if name == 'alex':continue
#     print(name)

# for+else
# names=['egon','kevin','alex','hulaoshi']
# for name in names:
#     # if name == 'alex':break
#     print(name)
# else:
#     print('=====>')

# for循环嵌套
# for i in range(3): #i=2
#     for j in range(2): #j=1
#         print(i,j) #2,1


'''
外层循环第一次:i=0
    内层循环
        0,0
        0,1
        
外层循环第二次:i=1
    内层循环
        1,0
        1,1
外层循环第三次: i=2
    内层循环
        2,0
        2,1
        

'''

print(' ',end='')
print('bbbbb',end='')

数字类型

# 1. 整型int
# ======================================基本使用======================================
# 1、用途:记录年龄、等级、号码等

# 2、定义方式
age=10 # age=int(10)

# 类型转换
# print(int(3.1))
# res=int('1111111')
# print(res,type(res))

# res=float('111111.1')
# print(res,type(res))

# 了解(**)
# 十进制转成。。。进制
# print(bin(13))
# print(oct(13))
# print(hex(13))

# 3、常用操作+内置的方法

# ======================================该类型总结====================================
# 存一个值

# 不可变
# x=10
# print(id(x))
# x=11
# print(id(x))

# 1. 浮点型float
# ======================================基本使用======================================
# 1、用途:记录身高、体重、薪资等

# 2、定义方式
# salary=10.1 # salary=float(10.1)

# 类型转换
# print(float(10))
# print(float(1.1))
# print(float('1.1'))

# 3、常用操作+内置的方法

# ======================================该类型总结====================================
# 存一个值

# 不可变
x=10.3
print(id(x))
x=11.2
print(id(x))

字符串类型

# print(type(res2))
# print(type(res3))
# print(type(res4))

# 3、常用操作+内置的方法
#优先掌握的操作:(*****)
#1、按索引取值(正向取+反向取) :只能取
# msg='hello world'

# print(type(msg[0]))
# print(msg[-1])

# msg[0]='H'


#2、切片(顾头不顾尾,步长)
msg='hello world'
# print(msg[0]+msg[1]+msg[2])
# print(msg[0:5])
# print(msg[0:5:2]) #0 2 4
# print(msg[0:]) #
# print(msg[:]) #

#
# print(msg[-1:-5:-1]) #-1 -2 -3 -4
# print(msg[::-1]) #-1 -2 -3 -4

#3、长度len:统计的是字符的个数
# msg='h你d'
# print(len(msg))

#4、成员运算in和not in:判断一个子字符串是否存在与一个大字符串中
# msg='hello world'
# print('ho' in msg)
# print('ho' not in msg)


#5、移除空白strip:移除字符串左右两边的某些字符
# msg='      hello      '

# print(msg.strip(' '))
# print(msg.strip())
# print(msg)

# name=input('name>>>: ').strip() #name='egon'
# pwd=input('password>>>: ').strip()
#
# if name == 'egon' and pwd == '123':
#     print('login successfull')
# else:
#     print('username or password error')

# msg='***h**ello**********'
# print(msg.strip('*'))

# msg='*-=+h/ello*(_+__'
# print(msg.strip('*-=+/(_'))


#6、切分split: 把有规律的字符串切成列表从而方便取值
# info='egon:18:180:150'
# res=info.split(':',1)
# print(res)
# print(res[1])


# info='egon:18:180:150'
# res=info.split(':')
# print(res)


# s1=res[0]+':'+res[1]+':'+res[2]+':'+res[3]
# s1=''
# for item in res:
#     s1+=item
# print(s1)


# s1=':'.join(res)
# print(s1)

# ':'.join([1,2,3,4,5])

#7、循环
# for i in 'hello':
#     print(i)

# 需要掌握的操作(****)
#1、strip,lstrip,rstrip
# msg='*****hello****'
# print(msg.strip('*'))
# print(msg.lstrip('*'))
# print(msg.rstrip('*'))

#2、lower,upper
# msg='AaBbCc123123123'
# print(msg.lower())
# print(msg.upper())

#3、startswith,endswith
# msg='alex is dsb'
# print(msg.startswith('alex'))
# print(msg.endswith('sb'))

#4、format的三种玩法
# msg='my name is %s my age is %s' %('egon',18)
# print(msg)

# msg='my name is {name} my age is {age}'.format(age=18,name='egon')
# print(msg)

# 了解
# msg='my name is {} my age is {}'.format(18,'egon')
# msg='my name is {0}{0} my age is {1}{1}{1}'.format(18,'egon')
# print(msg)


#5、split,rsplit
# cmd='get|a.txt|33333'
# print(cmd.split('|',1))
# print(cmd.rsplit('|',1))


#6、replace
# msg='kevin is sb kevin kevin'
# print(msg.replace('kevin','sb',2))

#7、isdigit #当字符串内为纯数字时结果为True
# res='11111'
# print(res.isdigit())
# int(res)

# age_of_bk=18
# inp_age=input('your age: ').strip()
# if inp_age.isdigit():
#     inp_age=int(inp_age) #int('asdfasdfadfasdf')
#     if inp_age > 18:
#         print('too big')
#     elif inp_age < 18:
#         print('to small')
#     else:
#         print('you got it')
# else:
#     print('必须输入纯数字')


# 了解(**)
#1、find,rfind,index,rindex,count
# print('xxxkevin is sb kevin'.find('kevin'))
# print('xxxkevin is sb kevin'.index('kevin'))
# print('xxxkevin is sb kevin'.rfind('kevin'))
# print('xxxkevin is sb kevin'.rindex('kevin'))
#

# res='xxxkevin is sb kevin'.find('kevasdfsadfin')
# print(res)

# res='xxxkevin is sb kevin'.index('kevasdfsadfin')


# print('kevin is kevin is kevin is sb'.count('kevin'))

#2、center,ljust,rjust,zfill
# print('egon'.center(50,'*'))
# print('egon'.ljust(50,'*'))
# print('egon'.rjust(50,'*'))
# print('egon'.zfill(50))

#3、captalize,swapcase,title
# print('my name is kevin'.capitalize())
# print('AaBbCc'.swapcase())
# print('my name is kevin'.title())

#4、is其他
# name='egon123'
# print(name.isalnum()) #字符串由字母或数字组成
# print(name.isalpha()) #字符串只由字母组成

# print(name.islower())
# print(name.isupper())
# name='    '
# print(name.isspace())
msg='I Am Egon'
print(msg.istitle())

# ======================================该类型总结====================================
# 存一个值

# 有序

# 不可变(1、可变:值变,id不变。可变==不可hash 2、不可变:值变,id就变。不可变==可hash)
# x='aaa'
# print(id(x))
# x='bbb'
# print(id(x))

  

原文地址:https://www.cnblogs.com/wangmiaolu/p/10023436.html