Dictionaries_Access.py

# Python - Access Dictionary Items

# Accessing Items
# You can access the items of a dictionary by referring to its key name, inside square brackets:

# Example
# Get the value of the "model" key:

thisdict = {
  "brand": "Ford",
  "model": "Mustang",
  "year": 1964
}
x = thisdict["model"]

# There is also a method called get() that will give you the same result:

# Example
# Get the value of the "model" key:

x = thisdict.get("model")

# Get Keys
# The keys() method will return a list of all the keys in the dictionary.

# Example
# Get a list of the keys:

x = thisdict.keys()

# The list of the keys is a view of the dictionary, meaning that any changes done to the dictionary will be reflected in the keys list.

# Example
# Add a new item to the original dictionary, and see that the keys list gets updated as well:

car = {
"brand": "Ford",
"model": "Mustang",
"year": 1964
}

x = car.keys()

print(x) #before the change

car["color"] = "white"

print(x) #after the change

# Get Values
# The values() method will return a list of all the values in the dictionary.

# Example
# Get a list of the values:

x = thisdict.values()
# The list of the values is a view of the dictionary, meaning that any changes done to the dictionary will be reflected in the values list.

# Example
# Make a change in the original dictionary, and see that the values list gets updated as well:

car = {
"brand": "Ford",
"model": "Mustang",
"year": 1964
}

x = car.values()

print(x) #before the change

car["year"] = 2020

print(x) #after the change

# Example
# Add a new item to the original dictionary, and see that the values list gets updated as well:

car = {
"brand": "Ford",
"model": "Mustang",
"year": 1964
}

x = car.values()

print(x) #before the change

car["color"] = "red"

print(x) #after the change

# Get Items
# The items() method will return each item in a dictionary, as tuples in a list.

# Example
# Get a list of the key:value pairs

x = thisdict.items()

# The returned list is a view of the items of the dictionary, meaning that any changes done to the dictionary will be reflected in the items list.

# Example
# Make a change in the original dictionary, and see that the items list gets updated as well:

car = {
"brand": "Ford",
"model": "Mustang",
"year": 1964
}

x = car.items()

print(x) #before the change

car["year"] = 2020

print(x) #after the change

# Example
# Add a new item to the original dictionary, and see that the items list gets updated as well:

car = {
"brand": "Ford",
"model": "Mustang",
"year": 1964
}

x = car.items()

print(x) #before the change

car["color"] = "red"

print(x) #after the change

# Check if Key Exists
# To determine if a specified key is present in a dictionary use the in keyword:

# Example
# Check if "model" is present in the dictionary:

thisdict = {
  "brand": "Ford",
  "model": "Mustang",
  "year": 1964
}
if "model" in thisdict:
  print("Yes, 'model' is one of the keys in the thisdict dictionary")