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Python Python Collections (Retired) Tuples Combo

Chris Komaroff
PLUS
Chris Komaroff
Courses Plus Student 14,198 Points

Is teacher's answer for Tuples with Functions challenge 1 of 1 correct? "Bummer expected (10,T)" is wrong?

Challenge 1 of 1 code comment:

combo([1, 2, 3], 'abc')

Output:

[(1, 'a'), (2, 'b'), (3, 'c')]

If you use .append(), you'll want to pass it a tuple of new values

That's what my function combo() gives. I tested in workspace. Not following this.

zippy.py
# combo([1, 2, 3], 'abc')
# Output:
# [(1, 'a'), (2, 'b'), (3, 'c')]
# If you use .append(), you'll want to pass it a tuple of new values.

def combo( iter1, iter2 ):
  return_list = []
  temp_dict = {}
  list_len = len( iter1 )
  i = 0
  while i < list_len:
    temp_dict[ iter1[i] ] = iter2[i]
    i += 1
  for key, value in temp_dict.items():
    return_list.append( (key,value) )
  return return_list

1 Answer

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,441 Points

The ordering of items found when iterating on a dictionary can not be guaranteed. By constructing a temp_dict then reading key/value pairs out, you are scrambling the tuple order. Instead you can build add append the tuples directly

def combo( iter1, iter2 ):
    return_list = []
    list_len = len( iter1 )
    i = 0
    while i < list_len:
        return_list.append((iter1[i], iter2[i]))
        i += 1
    return return_list
Chris Freeman
Chris Freeman
Treehouse Moderator 68,441 Points

There are many ways to improve on this code:

def combo( iter1, iter2 ):
    return_list = []
    for idx, item in enumerate(iter1):
        return_list.append((item, iter2[idx]))
    return return_list

Or....

def combo( iter1, iter2 ):
    return list(zip(iter1, iter2))