name = ‘alex‘
# 首字母大写
print(name.capitalize())
name = ‘ALex Li english hahae‘
# 首字母小写
print(name.casefold())
# 指定长度居中，用=补齐
print(name.center(10, ‘=‘))
# 制定范围统计
print(name.count(‘e‘, 0, 5))
# 判断是否以指定字符串结尾
print(name.endswith(‘ae‘))
name = ‘alex\tLi‘
 # 指定tab键占用的空格数
print(name.expandtabs(20))
# 指定字符串在原字符串中的位置
print(name.find(‘Li‘))
# 格式化赋值
msg = "my name is {0}, and i am {1} years old"
msg2 = "my name is {name}, and i am {age} years old"
print(msg.format(‘alex‘,22))
print(msg2.format(age=22, name=‘jack‘))
# 是否英文字母
print(‘ad‘.isalpha())
# 是否数字和字母
print(‘a3d‘.isalnum())
# 是否十进制
print(‘2‘.isdecimal())
# 是否正整数
print(‘2‘.isdigit()) 
# 是否合法的变量名
print(‘al_ex‘.isidentifier()) 
# 是否小写
print(‘al_ex‘.islower()) 
# 是否大写
print(‘al_ex‘.isupper()) 
# 是否数字
print(‘3‘.isnumeric()) 
# 是否可打印
print(‘3‘.isprintable()) 
# 是否数字
print(‘3‘.isnumeric()) 
# 每个单子首字母是否大写
print(‘My Name Is Alex‘.istitle())
# 将列表所有元素用，连接成一个字符串，作用与split相反
print(‘,‘.join([‘alex‘,‘jack‘,‘rain‘]))
# 左对齐
print(‘3‘.ljust(50,‘-‘))
# 右对齐
print(‘3‘.rjust(50,‘-‘))
# 字符串小写
print(‘Alex‘.lower())
# 左边去空格
print(‘    Alex  \n‘.lstrip())
# 右边去空格和回车
print(‘    Alex  \n‘.rstrip())
# 创建一个转义规则，根据规则转义字符串
from_str = ‘!@#$%^&‘
to_str = ‘abcdefg‘
trans_table = str.maketrans(to_str,from_str)
str = ‘alex‘
str.translate(trans_table)
# 根据指定的字符串分割字符串
print(‘alex li‘.partition(‘e‘))
# 替换字符串内容
print(‘alex li‘.replace(‘l‘,‘L‘,1))
# 以换行符分割字符串
print("alex\n l\ni".splitlines())
# 默认以空格为分隔符分割字符串
print("alex\n l\ni".split())
# 右对齐，用0填充
print(‘alex li‘.zfill(40))

names = [‘alex‘, ‘jack‘, ‘rain‘, ‘mack‘, ‘rain‘, ‘bob‘]
# 切片
print(names[1:4:2])
print(names[-2:])
print(names[:2])
# 查找索引
first_index = names.index("rain")
# 查找第二个重复值rain的索引
second_index = names[first_index+1:].index("rain")
print(first_index, second_index)
# 删除列表元素
del names[first_index+second_index+1]
print(names)
# 删除
names.pop(4)
print(names)
# 修改列表元素值
names[4] = "Jason"
print(names)
# 列表相加
names += [1, 2, 3, 4]
print(names.extend([1, 2, 3, 4]))
print(names)
# 列表的嵌套与取值
names2 = [[‘alex‘, 22, [‘Teacher‘, 3000]], [‘oldboy‘, 56]]
print(names2)
print(names2[0][1])
names2[0][2][1] = 30000
print(names2)

names = {
    ‘stu1101‘: {‘name‘:‘Alex‘,‘age‘:22,‘hobbie‘:‘girl‘},
    ‘stu1102‘: ‘Jack‘,
    ‘stu1103‘: ‘rain‘,
}
# search
print(names[‘stu1101‘][‘hobbie‘])
# print(names[‘stu1104‘])
print(names.get(‘stu1104‘,‘sdfsdf‘))

# add
names[‘stu1104‘] = [‘yangJian‘,31,‘DBA‘]

# update
names[‘stu1104‘][0] = ‘wescker‘
print(names)

# delete
print(names.pop(‘stu1105‘,‘ssss‘))
del names[‘stu1103‘]
print(names)