Python列表、元组、集合、字典的区别和相互转换

列表、元组、集合、字典的区别

	列表	元组	集合	字典
英文	list	tuple	set	dict
可否读写	读写	只读	读写	读写
可否重复	是	是	否	是
存储方式	值	值	键(不能重复)	键值对(键不能重复)
是否有序	有序	有序	无序	无序，自动正序
初始化	[1,"a"]	("a", 1)	set([1,2]) 或 {1,2}	{"a":1,"b":2}
添加	append	只读	add	d["key"] = "value"
读元素	l[2:]	t[0]	无	d["a"]

列表、元组、集合、字典相互转换

列表元组转其他

# 列表转集合(去重)
list1 = [6, 7, 7, 8, 8, 9]
set(list1)
# {6, 7, 8, 9}

#两个列表转字典
list1 = ["key1","key2","key3"]
list2 = ["1","2","3"]
dict(zip(list1,list2))
# {"key1": "1", "key2": "2", "key3": "3"}

#嵌套列表转字典
list3 = [["key1","value1"],["key2","value2"],["key3","value3"]]
dict(list3)
# {"key1": "value1", "key2": "value2", "key3": "value3"}

# 列表、元组转字符串
list2 = ["a", "a", "b"]
"".join(list2)
# "aab"

tup1 = ("a", "a", "b")
"".join(tup1)
# "aab"

字典转其他

# 字典转换为字符串
dic1 = {"a":1,"b":2}
str(dic1)
# "{"a": 1, "b": 2}"

# 字典key和value互转
dic2 = {"a": 1, "b": 2, "c": 3}
{value:key for key, value in a_dict.items()}
# {1: "a", 2: "b", 3: "c"}

字符串转其他

# 字符串转列表
s = "aabbcc"
list(s)
# ["a", "a", "b", "b", "c", "c"]

# 字符串转元组
tuple(s)
# ("a", "a", "b", "b", "c", "c")

# 字符串转集合
set(s)
# {"a", "b", "c"}

# 字符串转字典
dic2 = eval("{"name":"ljq", "age":24}")

# 切分字符串
a = "a b c"
a.split(" ")
# ["a", "b", "c"]

参考地址：
https://docs.python.org/2/library/index.html