Dictionaries With Loops

 

Dictionaries With Loops

Loops and lists are a perfect pair. Dictionaries and loops are a bit trickier. This is because each dictionary item is made up of two parts - the name of the key and the actual value of that key.

I've Lost My Keys!

Let's set up a looped dictionary.

Using a for loop, like we would with a list, will output the values, but not the keys. Not ideal.

myDictionary = {"name" : "Ian", "health": 219, "strength": 199, "equipped": "Axe"}

for i in myDictionary:

  print(myDictionary[i])

This loop uses the values() method, which can be run on a data type. We still only get the value, and not the key.

myDictionary = {"name" : "Ian", "health": 219, "strength": 199, "equipped": "Axe"}

for value in myDictionary.values():

  print(value)

I've Got The Key...I've Got The Secret

There is a better way!
Here's a loop that will output both key and value.
The .items() function returns the key name and value. Note that I've supplied the loop with two arguments: 'name' and 'value').
This example will just output the names and values using an fString.

myDictionary = {"name" : "Ian", "health": 219, "strength": 199, "equipped": "Axe"}

for name,value in myDictionary.items():

  print(f"{name}:{value}")

A Bit Iffy
Let's go one step further and use some if statements inside the loop.
This example makes a comment about the strength key.

myDictionary = {"name" : "Ian", "health": 219, "strength": 199, "equipped": "Axe"}

for name,value in myDictionary.items():

  print(f"{name}:{value}")

  if (name == "strength"):

    print("Whoa, SO STRONG!")

This example uses nested if statements to react to the key name and the value stored within it.

myDictionary = {"name" : "David the Mildy Terrifying", "health": 186, "strength": 4, "equipped":"l33t haxx0r p0werz"}

for name, value in myDictionary.items():

print(f"{name}: {value}")

if (name == "strength"): 

if value > 100: # This nested if wasn't indented properly

  print("Whoa, SO STRONG")

else:

  print("Looks like you skipped leg day, arm day, chest day and, well, gym day entirely bro!")

Coding Challenge

Create a dictionary that stores the following information about a website: name, URL, description and a star rating (out of 5).
Use a loop to output the names of the keys, ask the user to type in the details and store the input in the dictionary.
Finally, output the whole dictionary (keys and values).

website = {"name": None, "url": None, "desc": None, "rating": None}

for name in website.keys():

  website[name] = input(f"{name}: ")

print()

for name, value in website.items():

  print(f"{name}: {value}")

Coding Challenge

Create a dictionary to store the details of your, ahem, MokéBeast.
Ask the user to input the following details: name, type (earth, fire, air, water or spirit), special move, starting HP and starting MP. For now we're just taking in one set of values for one beast.
Output the beast's details.
Check the beast's type and change the color of the text accordingly. Fire is red, water is blue, air is white. You decide on the others.

mokedex = {"Beast Name": None, "Type": None, "Special Move": None, "HP": None, "MP": None}

print("MokéBeast")

print()

for name, value in mokedex.items():

  mokedex[name] = input(f"{name}:\t").strip().title()

if mokedex["Type"]=="Earth":

  print("\033[32m", end="")

elif mokedex["Type"]=="Air":

  print("\033[37m", end="")

elif mokedex["Type"]=="Fire":

  print("\033[31m", end="")

elif mokedex["Type"]=="Water":

  print("\033[34m", end="")

else:

  print("\033[33m", end="")

for name, value in mokedex.items():

  print(f"{name:<15}: {value}")