Python dict遍历

# 定义一个字典
my_dict = {'a': 1, 'b': 2, 'c': 3}

# 遍历字典的键
for key in my_dict.keys():
    print(key)

a
b
c

# 定义一个字典
my_dict = {'a': 1, 'b': 2, 'c': 3}

# 遍历字典的值
for value in my_dict.values():
    print(value)

1
2
3

# 定义一个字典
my_dict = {'a': 1, 'b': 2, 'c': 3}

# 遍历字典的键值对
for key, value in my_dict.items():
    print(f'key: {key}, value: {value}')

key: a, value: 1
key: b, value: 2
key: c, value: 3

# 定义一个字典
my_dict = {'a': 1, 'b': 2, 'c': 3}

# 遍历字典的键值对并修改值
for key, value in my_dict.items():
    my_dict[key] = value * 2

print(my_dict)

{'a': 2, 'b': 4, 'c': 6}

# 定义一个字典
my_dict = {'a': 1, 'b': 2, 'c': 3}

# 遍历字典的键值对并删除值为奇数的键值对
for key, value in list(my_dict.items()):
    if value % 2 != 0:
        del my_dict[key]

print(my_dict)

{'b': 2}

# 定义一个字典
my_dict = {'a': 1, 'b': 2, 'c': 3}

# 遍历字典的键值对并新建一个值为偶数的新字典
new_dict = {k: v for k, v in my_dict.items() if v % 2 == 0}

print(new_dict)

{'b': 2}