没看懂代码，想查看帮助，结果杯具了……
>>> letters = {'g':1, 'o':2, 'd':1}>>> for letter in letters.keys():
for i in range(letters):
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 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
>>>
页:
[1]