Python基础学习-字典以及字典推导

字典

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# 空字典
map1 = {}
print(type(map1))

# 给字段赋值
map2 = {'x': 1, 'y': 2}
print(map2)

# 给字典添加值
map2['z'] = 3
print(map2)

输出结果：

<class 'dict'>
{'x': 1, 'y': 2}
{'x': 1, 'y': 2, 'z': 3}

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字典推导

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如果不用字典推导,想给一个字典初始化值的话，得像下面这么做：

# 空字典
map1 = {}

# 初始化字典
for i in range(1, 11):
    map1[i] = 0

print(map1)

输出结果如下：

{1: 0, 2: 0, 3: 0, 4: 0, 5: 0, 6: 0, 7: 0, 8: 0, 9: 0, 10: 0}

如果使用字典推导，则简洁很多。

# 使用推导为字典赋值
map1 = {i: 0 for i in range(1, 11)}
print(map1)

输出结果如下：

{1: 0, 2: 0, 3: 0, 4: 0, 5: 0, 6: 0, 7: 0, 8: 0, 9: 0, 10: 0}