What is the .item() doing?

Question

https://teamtreehouse.com/library/python-collections/dictionaries/teacher-stats

The question is: "...create a function name stats that takes the teacher dictionary. Return a list of lists in the format [<teacher name>, <number of classes>].

def stats(dict):
    a_list = []
    for teacher, class_num in dict.items():
        new_string = [teacher, len(class_num)]
        a_list.append(new_string)
    return a_list

The above code works. But I'm not clear on why the .items() is there. Please help.

teachers.py

# The dictionary will be something like:
# {'Jason Seifer': ['Ruby Foundations', 'Ruby on Rails Forms', 'Technology Foundations'],
#  'Kenneth Love': ['Python Basics', 'Python Collections']}
#
# Often, it's a good idea to hold onto a max_count variable.
# Update it when you find a teacher with more classes than
# the current count. Better hold onto the teacher name somewhere
# too!
#
# Your code goes below here.
def most_classes(dict):
  most_teach = ""
  current_count = 0
  for teacher in dict:
    if len(dict[teacher]) > current_count:
      current_count = len(dict[teacher])
      most_teach = teacher
  return most_teach

Answer 1 · 2016-03-31T04:23:18Z

March 31, 2016 4:23am

When a dictionary is used in an iterator context such as if a for loop, the default action is to iterate over the keys of the dict.

# these are equivalent statements
if teacher in teachers:

if teacher in teachers.keys()

There are two other ways to iterate a dictionary, by the *values using the .values() method, and by iterating over *both keys and values using the .items() method.

The .items() method will return two objects: a key and its corresponding value. This is why the for loop as two loop variables. The first receives the key, the second receives the value.

So instead of getting just the key then looking up the value, by using items() you can get the both at the same time which can be faster and less coding.

Welcome to the Treehouse Community

Looking to learn something new?

Gary Gibson

Gary Gibson

What is the .item() doing?

1 Answer

Chris Freeman

Chris Freeman

Gary Gibson

Gary Gibson