A python solution of "count and say" from leetcode went wrong

Question

class Solution:
    # @param n, an integer
    # @return a string
    def countAndSay(self, n):
        def f(string):
            a = []
            count_1 = 1
            count_2 = 1
            s = string[1:] + 'e'                                    #calculate i from string[1](this is to disregard the case of string[0]), meanwhile add 'e' to notify the end of the string
            for i, j in enumerate(s):

                if j == '1':
                    if string[i] == '1':                            #check whether the last member in string is the same as j
                        count_1 += 1                                #if so, count_1 add 1, save for further list appending
                    else:
                        count_1 = 1                                 #reset the count if last character does not match with j
                        a.append[(str(count_2) + '2')]              

                if j == '2':
                    if string[i] == '2':
                        count_2 += 1
                    else:
                        count_2 = 1
                        a.append[(str(count_1) + '1')]

                if j == 'e':                                         #j=='e' if the iteration reach the end, and it is the right time for adding the final member of the expected list
                    if string[i] == '1':                            
                        a.append[(str(count_1) + '1')]
                    if string[i] == '2':
                        a.append[(str(count_2) + '2')]

                return ''.join(list)

        def seq(n): 
            if n == 1:
                return '1'
            if n == 2:
                return '11'
            if n == 3:
                return '21'
            else:
                return f(seq(n-1))

        return seq(n)

This is a solution of a problem from leetcode: https://leetcode.com/problems/count-and-say/

It notifies me that:

Runtime Error Message: Line 17: TypeError: 'builtin_function_or_method' object has no attribute 'getitem'

Last executed input: 4

Line 17 comes as follows:

a.append[(str(count_2) + '2')]

Please, I am a completely novice and don't know how to solve this problem. Also, I would like you to improve my code as well. Thank you so much.

What are you expecting a.append[(str(count_2) + '2')] to do, exactly? Perhaps you should read e.g. docs.python.org/2/tutorial/datastructures.html#more-on-lists — jonrsharpe
– jonrsharpe, Commented Apr 17, 2015 at 13:52
We need to know what you're passing in to string, also return ''.join(list) should probably be outside the loop in f(), where is list coming from? There's a lot going on here... — MrAlexBailey
– MrAlexBailey, Commented Apr 17, 2015 at 13:52
I think it is okay for me to use "a.append[(str(count_2) + '2')]", to add element for my list. I will join the members of the list after then to produce the string. — tonyabracadabra
– tonyabracadabra, Commented Apr 17, 2015 at 14:02

Konstantin · Accepted Answer · 2015-04-17 14:07:04Z

1

Well, it is clear, that line 17 should look like

a.append(str(count_2) + '2')

See documentation on lists

When you use square brackets (a.append[key]) Python will try to call __getitem__ method on a.append

answered Apr 17, 2015 at 14:07

Konstantin

25.5k5 gold badges53 silver badges65 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

tonyabracadabra Over a year ago

Thank you. I overlooked.

Collectives™ on Stack Overflow

A python solution of "count and say" from leetcode went wrong

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related