Issue with dict() in Python, TypeError:'tuple' object is not callable

Question

I'm trying to make a function that will take an arbritrary number of dictionary inputs and create a new dictionary with all inputs included. If two keys are the same, the value should be a list with both values in it. I've succeded in doing this-- however, I'm having problems with the dict() function. If I manually perform the dict function in the python shell, I'm able to make a new dictionary without any problems; however, when this is embedded in my function, I get a TypeError. Here is my code below:

#Module 6 Written Homework
#Problem 4

dict1= {'Fred':'555-1231','Andy':'555-1195','Sue':'555-2193'}
dict2= {'Fred':'555-1234','John':'555-3195','Karen':'555-2793'}

def dictcomb(*dict):
    mykeys = []
    myvalues = []
    tupl = ()
    tuplist = []
    newtlist = []
    count = 0
    for i in dict:
        mykeys.append(list(i.keys()))
        myvalues.append(list(i.values()))
        dictlen = len(i)
        count = count + 1
    for y in range(count):
        for z in range(dictlen):
            tuplist.append((mykeys[y][z],myvalues[y][z]))
    tuplist.sort()
    for a in range(len(tuplist)):
        try:
            if tuplist[a][0]==tuplist[a+1][0]:
                comblist = [tuplist[a][1],tuplist[a+1][1]]
                newtlist.append(tuple([tuplist[a][0],comblist]))
                del(tuplist[a+1])
            else:
                newtlist.append(tuplist[a])
        except IndexError as msg:
            pass
    print(newtlist)
    dict(newtlist)

The error I get is as follows:

Traceback (most recent call last):
  File "<pyshell#17>", line 1, in <module>
    dictcomb(dict1,dict2)
  File "C:\Python33\M6HW4.py", line 34, in dictcomb
    dict(newtlist)
TypeError: 'tuple' object is not callable

As I described above, in the python shell, print(newtlist) gives:

[('Andy', '555-1195'), ('Fred', ['555-1231', '555-1234']), ('John', '555-3195'),     ('Karen', '555-2793')]

If I copy and paste this output into the dict() function:

dict([('Andy', '555-1195'), ('Fred', ['555-1231', '555-1234']), ('John', '555-3195'), ('Karen', '555-2793')])

The output becomes what I want, which is:

{'Karen': '555-2793', 'Andy': '555-1195', 'Fred': ['555-1231', '555-1234'], 'John': '555-3195'}

No matter what I try, I can't reproduce this within my function. Please help me out! Thank you!

Answer 1

A typical example of why keywords should not be used as variable names. Here dict(newtlist) is trying to call the dict() builtin python, but there is a conflicting local variable dict . Rename that variable to fix the issue.

Something like this:

def dictcomb(*dct): #changed the local variable dict to dct and its references henceforth
    mykeys = []
    myvalues = []
    tupl = ()
    tuplist = []
    newtlist = []
    count = 0
    for i in dct:
        mykeys.append(list(i.keys()))
        myvalues.append(list(i.values()))
        dictlen = len(i)
        count = count + 1
    for y in range(count):
        for z in range(dictlen):
            tuplist.append((mykeys[y][z],myvalues[y][z]))
    tuplist.sort()
    for a in range(len(tuplist)):
        try:
            if tuplist[a][0]==tuplist[a+1][0]:
                comblist = [tuplist[a][1],tuplist[a+1][1]]
                newtlist.append(tuple([tuplist[a][0],comblist]))
                del(tuplist[a+1])
            else:
                newtlist.append(tuplist[a])
        except IndexError as msg:
            pass
    print(newtlist)
    dict(newtlist)

Answer 2

You function has a local variable called dict that comes from the function arguments and masks the built-in dict() function:

def dictcomb(*dict):
              ^
            change to something else, (*args is the typical name)

Answer 3

Do you need to implement this entirely yourself, or would it be okay to use defaultdict ? If so, you might do something like:

from collections import defaultdict

merged_collection = defaultdict(list)
collection_1= {'Fred':'555-1231','Andy':'555-1195','Sue':'555-2193'}
collection_2= {'Fred':'555-1234','John':'555-3195','Karen':'555-2793'}

for collection in (collection_1, collection_2):
    for name, number in collection.items():
        merged_collection[name].append(number)

for name, number in merged_collection.items(): 
    print(name, number)

John ['555-3195']
Andy ['555-1195']
Fred ['555-1231', '555-1234']
Sue ['555-2193']
Karen ['555-2793']