python 列表，元组，字典，集合，字符串相互转换_python转换字典列表某一列的字符怎么写

1. 列表与元组的互换

将列表转化为元组

li = [1, 2, 3]
t = tuple(li)
print(t, type(t))

打印结果:(1, 2, 3) <class ‘tuple’>

将元组转换成列表

tu = (1, 2, 3)
li = list(tu)
print(li, type(li))

打印结果:[1, 2, 3] <class ‘list’>

2. 列表与字符串的互换

列表转换成字符串

li = [‘人’, ‘生’, ‘苦’, ‘短’]
str1 = ‘’.join(li)
print(str1, type(str1))

输出结果：人生苦短 <class ‘str’>

字符串转换成列表

str2 = ‘hello python’
li1 = str2.split(’ ')
print(li1, type(li1))

输出结果：[‘hello’, ‘python’] <class ‘list’>

3. 列表与字典转换

列表转字典方式一

list1 = [‘name’, ‘age’, ‘sex’]
list2 = [‘张三’, 18, ‘男’]
dict = {}
for i in range(len(list1)):
dict[list1[i]] = list2[i]
print(dict, type(dict))

输出结果：{‘name’: ‘张三’, ‘age’: 18, ‘sex’: ‘男’} <class ‘dict’>

列表转字典方式二：使用内置函数zip

list1 = [‘name’, ‘age’, ‘sex’]
list2 = [‘张三’, 18, ‘男’]
d = dict(zip(list1, list2))
print(d)

字典转换成列表

dict = {‘name’: ‘张三’, ‘age’: 18, ‘sex’: ‘男’}
keys = list(dict.keys())
values = list(dict.values())
print(keys, type(keys))
print(values, type(values))
4.嵌套列表转字典

list3 = [[‘key1’,‘value1’],[‘key2’,‘value2’],[‘key3’,‘value3’]]
print(dict(list3))
5. 列表与集合转换

列表转集合

list1 = [1, 3, 4, 3, 2, 1]
s1 = set(list1)
print(s1, type(s1))

输出结果：{1, 2, 3, 4} <class ‘set’>

集合转列表

list2 = list(s1.intersection(s1))
print(list2, type(list2))

输出结果：[1, 2, 3, 4] <class ‘list’>

6. 元组和字符串转换

元组转换成字符串和列表方法一样

字符串转换成元组，需要将字符串转换成列表，在利用列表转成元组

list = []
a = ‘人生苦短’
list.append(a)
print(list)
b = tuple(list)
print(b, type(b))

输出结果：(‘人生苦短’,) <class ‘tuple’>

7.元组和字典转换

字典转元组

dict = {‘name’: ‘xiaoming’, ‘age’: 18}
tup = tuple(dict)
print(tup) # 只转换了key

tup2 = tuple(dict.values())
print(tup2)

元组不能转成字典

8.字典和字符串转换

字典转换为字符串

dic1 = {‘a’: 1, ‘b’: 2}
str1 = str(dic1)

输出结果：{‘a’: 1, ‘b’: 2} <class ‘str’>

字符串转字典

dic2 = eval(“{‘name’:‘xiaoming’, ‘age’:18}”)
print(dic2, type(dic2))
9.字符串和集合转换

字符串转集合

str1 = ‘hello’
s1 = set(str1)
print(s1, type(s1))

输出结果：{‘e’, ‘o’, ‘h’, ‘l’} <class ‘set’>

10.字典key和value值转换

dic1 = {‘a’: 1, ‘b’: 2, ‘c’: 3}
dic2 = {value: key for key, value in dic1.items()}
print(dic2)