Python_07_day

str

1、# capitalize 首字母大写，其余变小写
s1 = 'taiBAi'
print(s1.capitalize())

2、# swapcase  大小写翻转
s1 = 'taiBAi'
print(s1.swapcase())

3、#每个单词的首字母大写title
msg= 'taibai say3hi'
print(msg.title())

4、# 居中
s1 = 'barry'
print(s1.center(20))
print(s1.center(20,'*'))

5、# find :通过元素找索引，找到第一个就返回，找不到 返回-1
s1 = 'barry'
print(s1.find('a'))
print(s1.find('o'))

6、# index:通过元素找索引，找到第一个就返回，找不到 报错
s1 = 'barry'
print(s1.index('r'))
print(s1.index('o'))

元组

1、# 元组中如果只有一个元素，并且没有逗号，那么它不是元组，它与该元素的数据类型一致
tu1 = (2)
print(tu1,type(tu1))
tu2 = (2,)
print(tu2,type(tu2))

2、# count 计数
tu = (1,2,3,3,3,2,2,3,)
print(tu.count(3))

3、# index 索引
tu = ('太白', '日天', '太白')
print(tu.index('太白'))

列表

1、#count 计数 
l1 = [5, 4, 3, 7, 3 ,4 ,3 ,8, 6, 1, 9]
print(l1.count(3))

2、# index 索引
l1 = ['太白', '123', '女神', '大壮']
print(l1.index('大壮'))

3、# 默认从小到大排序
l1 = [5, 4, 3, 7, 8, 6, 1, 9]
l1.sort()
print(l1)

4、# 从大到小排序
l1 = [5, 4, 3, 7, 8, 6, 1, 9]
l1.sort(reverse=True)
print(l1)

5、# 列表相加
l1 = [1, 2, 3]
l2 = ['太白', '123', '女神']
print(l1 + l2)

6、#列表与数字相乘
l1 = [1, 'daf', 3]
l2 = l1*3
print(l2)

字典

1、#字典的更新
dic = {'name': '太白', 'age': 18}
dic.update(hobby='运动', hight='175')
print(dic)

dic = {'name': '太白', 'age': 18}
dic.update([(1, 'a'),(2, 'b'),(3, 'c'),(4, 'd')])
print(dic)

# 更新，有则覆盖，无则添加
dic1 = {"name":"jin","age":18,"sex":"male"}
dic2 = {"name":"alex","weight":75}
dic1.update(dic2)

2、# fromkeys创建字典
dic = dict.fromkeys('abc', 100)
print(dic)

dic = dict.fromkeys([1, 2, 3], 'alex')
print(dic)

dic = dict.fromkeys([1,2,3],[6, 7, 8])
print(dic)