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>>> letters = {'g':1, 'o':2, 'd':1}
>>> for letter in letters.keys():
for i in range(letters[letter]):
print(letter)
g
o
o
d
>>> print(keys)
Traceback (most recent call last):
File "<pyshell#25>", line 1, in <module>
print(keys)
NameError: name 'keys' is not defined
>>> help(keys)
Traceback (most recent call last):
File "<pyshell#26>", line 1, in <module>
help(keys)
NameError: name 'keys' is not defined
请大神指点下:
1、代码中红色部分什么意思?
2、遇到看不懂的,应如何查询用法?不是用print或help吗?
letters.keys() 是 letters 中的所有键,而 letters[letter] 就是 letters 中 letter 键对应的值。
如果遇到不会的函数,可以通过 help 查询,语法问题可以来论坛问。
- >>> letters = {'g':1, 'o':2, 'd':1}
- >>> letters.keys()
- dict_keys(['g', 'o', 'd'])
- >>> letters['g']
- 1
- >>> letters['o']
- 2
- >>> letters['d']
- 1
- >>> help(letters.keys)
- Help on built-in function keys:
- keys(...) method of builtins.dict instance
- D.keys() -> a set-like object providing a view on D's keys
- >>>
复制代码
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