组合数据类型练习

分别定义字符串，列表，元组，字典，集合，并进行遍历。
# 字符串
sen = 'this'
print(type(sen))
print(sen)

# 数组
list1 = ['wher', 'is', 'you', 'cat', '?']
for i in list1:
    print(i)
print(len(list1))
print(type(list1))

# 元组
tu = tuple(list1)
print(tu)
print(type(tu))
for u in tu:
    print(u)
print(tu[2])

# 字典
di = {'a': 10, 'b': 20, 'c': 30}
print(di['hhh'])
# print(di)
for key in di:
    print((str(key) + ':' + str(di[key])))

# 集合
s = set([4, 3, 9, 9, 6, 6, 6])
#重复元素会被自动过滤
print(s)
s.add("a")
print(s)
for ss in s:
    print(ss)