我們希望的正常的使用：
下面示例是字串所以可以使用！

>>> k = 'good blue sky'
>>> k.capitalize()
'Good blue sky'

報錯的是因為你建立的不是字串，可能是一個列表！
類似這樣：

>>> ss = ['mode','in','china']
>>> ss.capitlize()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'list' object has no attribute 'capitlize'
 

那麼就要進行修改啦：

>>> [string.capitalize() for string in ss]
['Mode', 'In', 'China']
>>>

把列表變成sting就行啦！
類似集合，元組，字典都可以！
以下為示例：

>>> d = {'sd','blue'}#集合
>>> d.capitlize()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'set' object has no attribute 'capitlize'
>>> [string.capitalize() for string in d]
['Blue', 'Sd']

>>> c = ('asd','blue')#元組
>>> c.capitalize()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'tuple' object has no attribute 'capitalize'
>>> [string.capitalize() for string in c]
['Asd', 'Blue']
>>>

>>> a = {'abc':'wsd','ews':'edr'}#字典
>>> a.capitalize()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'dict' object has no attribute 'capitalize'
>>> [string.capitalize() for string in a]
['Abc', 'Ews']
>>>
 

集合：
元組：

字典：
只會大寫鍵！

其他函式類似，都是將其變成string格式再進行呼叫函式：
其他函式連結：
https://blog.csdn.net/weixin_42859280/article/details/84675684