今天学习内容总结

name = 'Jim'   # name = str('jim')
str1 = str(1.1)
str2 = str([1, 2,3])
print(f'str1:{str1} ,str1_type:{type(str1)}')
print(f'str2:{str2},str2_type:{type(str2)}')
'''
结果：
str1:1.1 ,str1:<class 'str'>
str2:[1, 2, 3],str2_type:<class 'str'>
自己总结：str（）或者单双引号定义之后在内存中就是字符串，不管是任何形式？
'''

name = 'Cyberpunk2077'
print(name[0])
print(name[-1])   #负数从有往左从1开始取值
print(name[2:5])   #顾头不顾尾切片
print(name[2:])    #不写默认到末尾
print(name[1:9:2])   #在位置1-9之间步长为2取值
print(name[2::-2])   #步长为负数从右往左取值
'''
结果：
C
yepn
C
7
ber
berpunk2077
yepn
bC
'''

name = " Cyber punk 2077 "
print(name.strip())
'''
结果：
Cyber punk 2077
默认去除两端的空格
'''

name = " Cyber pu:nk 2077 "
print(name.split())
print(name.split(':'))
'''
默认空格切割返回一个列表
['Cyber', 'pu:nk', '2077']
[' Cyber pu', 'nk 2077 ']
'''

name = ' Ji:m '
for i in name:
    print(i)
'''
 结果：

J
i
:
m
 
'''

name = 'Cyberpunk2077'
print(name.lower())
print(name.upper())

name = 'Cyberpunk2077'
print(name.startswith('c'))
print(name.endswith('7'))
'''
结果：
False
True
'''

year = '2077'
π = '3.14159'
print(year.isdigit())
print(π.isdigit())
'''
结果：
True
False
'''

str = "this is really a string example....wow!!!";
substr = "is";
print str.rfind(substr);
print str.rfind(substr, 0, 10);
print str.rfind(substr, 10, 0);

print str.find(substr);
print str.find(substr, 0, 10);
print str.find(substr, 10, 0);
'''
结果
5
5
-1
2
2
-1
'''