Python的6个小tips

1.反转字典

my_dict = {
    "brand": "Ford",
    "model": "Mustang",
    "year": 1964
}
print(dict(map(reversed, my_dict.items())))

2.对字典列表进行排序

dicts_lists = [
    {
        "Name": "James",
        "Age": 20
    },{
        "Name": "May",
        "Age": 14
    },{
        "Name": "Katy",
        "Age": 23
    }
]
dicts_lists.sort(key=lambda item: item.get("Age"))
print(dicts_lists)

3.根据另一个列表对列表进行排序

a = ["blue", "green", "orange", "purple", "yellow"]
b = [3, 2, 5, 4, 1]
sortedList = [val for (_, val) in sorted(zip(b, a), key=lambda x: x[0])]
print(sortedList)

4.把两个列表合并到一个字典

keys_list = ['A', 'B', 'C']
values_list = ['blue', 'red', 'bold']
dict_ = dict(zip(keys_list, values_list))
print(dict_)

5.对字符串列表进行排序

my_list = ["blue", "red", "green"]
# 根据字母顺序进行排序
my_list.sort()
print(my_list)
# 长度
print(sorted(my_list, key=len))

6.判断文件/文件夹是否存在

import os
# isfile:判断文件
# exists:判断文件夹
exists = os.path.isfile('F:\\python3114\\selenium\\test.py')
print(exists)