Dictionary Guide

Introduction to Dictionaries

Dictionaries are used to store data values in key:value pairs. A dictionary is a collection which is ordered*, changeable, and does not allow duplicates.

Example:

person = {
  "Name": "Manu",
  "Age": "42",
  "Phone": 90540977
}
print(person)

Methods for Dictionaries

keys()

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

Example:

print(person.keys())

values()

The values() method returns a view object. The view object contains the values of the dictionary, as a list.

Example:

print(person.values())

get()

The get() method returns the value of the item with the specified key.

• keyname: Required. The keyname of the item you want to return the value from.
• value: Optional. A value to return if the specified key does not exist. Default value is None.

Example:

print(person.get("Name"))
print(person.get("Address", "Not Available"))

pop()

The pop() method removes the specified item from the dictionary. The value of the removed item is the return value of the pop() method.

Example:

removed_value = person.pop("Age")
print(removed_value)
print(person)

popitem()

The popitem() method removes the item that was last inserted into the dictionary. In versions before 3.7, the popitem() method removes a random item.

Example:

last_item = person.popitem()
print(last_item)
print(person)

update()

The update() method inserts the specified items to the dictionary.

Example:

person.update({"Address": "123 Street Name"})
print(person)
thisdict = {
    "brand": "Ford",
    "model": "Mustang",
    "year": 1964
}

thisdict.update({"color": "red"})

item()

key and value

Adding Items

Adding an item to the dictionary is done by using a new index key and assigning a value to it:

Example: thisdict = { "brand": "Ford", "model": "Mustang", "year": 1964 } thisdict["color"] = "red" print(thisdict)

Dictionary Sorting

Example: thisdict = { "c": 7, "b": 2, "a": 5, "d": 8 } d = dict(sorted(thisdict.items)) print(d)

Dictionary iteration

Example: mydict = {"c": 7,"b": 2,"a": 5,"d": 8} for i,j in mydict.items(): print(i,j)

where i is key and j is value