元祖（tuple）的帮助文档

class tuple(object)
 |  tuple() -> empty tuple
 |  tuple(iterable) -> tuple initialized from iterable's items
 |
 |  If the argument is a tuple, the return value is the same object.
 |
 |  Methods defined here:
 |
 |  __add__(self, value, /)
 |      Return self+value.
 |
 |  __contains__(self, key, /)
 |      Return key in self.
 |
 |  __eq__(self, value, /)
 |      Return self==value.
 |
 |  __ge__(self, value, /)
 |      Return self>=value.
 |
 |  __getattribute__(self, name, /)
 |      Return getattr(self, name).
 |
 |  __getitem__(self, key, /)
 |      Return self[key].
 |
 |  __getnewargs__(...)
 |
 |  __gt__(self, value, /)
 |      Return self>value.
 |
 |  __hash__(self, /)
 |      Return hash(self).
 |
 |  __iter__(self, /)
 |      Implement iter(self).
 |
 |  __le__(self, value, /)
 |      Return self<=value.
 |
 |  __len__(self, /)
 |      Return len(self).
 |
 |  __lt__(self, value, /)
 |      Return self<value.
 |
 |  __mul__(self, value, /)
 |      Return self*value.n
 |
 |  __ne__(self, value, /)
 |      Return self!=value.
 |
 |  __new__(*args, **kwargs) from builtins.type
 |      Create and return a new object.  See help(type) for accurate signature.
 |
 |  __repr__(self, /)
 |      Return repr(self).
 |
 |  __rmul__(self, value, /)
 |      Return self*value.
 |
 |  count(...)  #元素个数统计
 |      T.count(value) -> integer -- return number of occurrences of value
 |
 |  index(...)  #查找元素下标
 |      T.index(value, [start, [stop]]) -> integer -- return first index of value.
 |      Raises ValueError if the value is not present.

其实tuple只有两个方法，count和index

>>> a
(1, 2, 3)
>>> a.count()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: count() takes exactly one argument (0 given)
>>> a.count(1)
1
>>> a = (1,1,1,2,3,4,5)
>>> a
(1, 1, 1, 2, 3, 4, 5)
>>> a.count(1)
3
>>> a.index(1)
0
>>> a.index(2)
3