Variable names and function arguments should be lowercase.
You should wrap your main procedure in a main function, as well as a if __name__ == '__main__' guard. More info.
Function and variable naming are important for readability of your code. The clearer and more accurate your naming, the quicker and easier your code can be understood. For example: ...
My opinion is that you should test better, before asking for code review.
line = " #Wartosc jest dodawana do listy pod hashowanym indeksem"
for word in line.split():
for c in content:
L[c] = c
Put a print statement inside each of your functions, for example print('__getitem__ ran'). Then keep ...