有关下面Python代码的说法，正确的是
class manyData:
def _init_(self, lstData):
self._data = lstData
def push(self, val):
self._data.append(val)
return self
def pop(self):
popVal = self._data[-1]
self._data.pop()
return popVal
def _len_(self):
return len(self._data)
myData = manyData([1, 2, 3])
myData.push(100)
print(len(myData))
print(myData.peek())
print(myData.pop())
