Comparing lists, tuples and maps

tuples-maps-intro.py

# a crude program to show examples of a tuple
# and relate to lists and strings

# a tuple is similar to a list, but uses parentheses

fibs = (0, 1, 1, 2, 3)
print(fibs[3])

# Above, we define the variable fibs as the numbers 0, 1, 1, 2, and 3.
# Just like a list, we print the item in the index position 3 in the tuple.

# The main difference between a tuple and a list is that you cannot
# change the tuple once you've created it.

# For example, if we try to replace an index position value in the tuple,
# we get an error message.

# fibs[0] = 4

# If we cannot change a tuple once we've created it,
# Why would we use a tuple instead of a list?

# I'm glad you asked,
# primarily, it's because sometimes it is useful to use something
# that you know can never change.
# If you create a tuple with two elements inside, it will
# always have those two elements.
# We can see the importance if we call on particular specifications (a tuple created in another program) of something in a program
# we are currently working in. In this way, tuples are more efficient than using a list. -we'll dive into that later.

# Python Maps Won't Help You Find Your Way -adapted from Jason Briggs Python for Kids
# In Python, a MAP (also referred to as a dict (or dictionary)
# is a collection of things, like lists and tuples.
# The difference between maps, tuples, and lists:
# each item in a map has a KEY and a corresponding VALUE.

# For example, say we have a list of company brands and what those brands make:

things_brands_make = ['IKEA, furniture', 'Ralph Lauren, clothing', 'General Motors, cars', 'Deer Park, bottled water', 'BIC, writing tools']

# Above, we put the information into a Python list, with the brand followed
# by what stuff that brand makes.

# If you were asked what things the brand, BIC makes, you can scan the list and find
# the answer to be writing tools.
# But, what if the list included 200 (or more) brands?
# -That would take up a lot more time!

# So, if we store the information in a map, with the brand's name as the key
# and what they make as the value,
# The Python code would look like this:

things_brands_make = {'IKEA' : 'furniture', 'Ralph Lauren' : 'clothing', 'General Motors' : 'cars', 'Deer Park' : 'bottled water', 'BIC' : 'writing tools'}

# We use colons to separate each key from its value, and each key and value is sectioned of wih single quotes.
# Notice too, the items in the map are enclosed by braces ({}),
# not parentheses, like a tuple, and not brackets like a list.

# The result of a map (each key maps to a particular value), can visualized as a table:

# | Brand Name     | Value         |
#   ______________  _____________
# | IKEA           | furniture     |
# | Ralph Lauren   | clothing      |
# | General Motors | cars          |
# | Deer Park      | bottled water |
# | Bic            | writing tools |

# Now, to get the type of things the brand, BIC makes,
# we access our map "things_brands_make" using the brand's name as the key,
# like this:

print(things_brands_make['BIC'])

# Python gives the answer, writing tools.

# To delete a value in the map, use its key.
# For example, I'll remove Deer Park:

del things_brands_make['Deer Park']
print(things_brands_make)

# Now, the key, Deer Park and its value, bottled water is not part of the map

# To replace a value in a map, we also use its key:

things_brands_make['Ralph Lauren'] = 'shoes'
print(things_brands_make)

# In other words, we replaced the thing that a brand makes with shoes
# by using the key Ralph Lauren.