Dictionary

Dictionary in Python

Dictionaries are used to store data values in key:value pairs.

Syntax :

 dictionary_name={
    key1:value1,
    key2:value2,
    key3:value3
}

Example 1 :

phoneBook = {
    "Dolly" : "1234567890",
    "Anu" : "9876543210",
    "Avinash" : "21323422222",
    "Pooja" : "878975457"
}
print(phoneBook)

Output :

{'Dolly': '1234567890', 'Anu': '9876543210', 'Avinash': '21323422222', 'Pooja': '878975457'}

Example Exaplanation :

The code defines a dictionary name phoneBook which contains key-value pairs where each key represents a name and each value represents a phone number. Output shows the entire phonebook dictionary with all the key-value pairs.

Example 2 :

phoneBook = {
    "Dolly" : "1234567890",
    "Anu" : "9876543210",
    "Avinash" : "21323422222",
    "Pooja" : "878975457"
}
print(phoneBook["Pooja"])

Output :

878975457

Example Explanation :

The code defines a dictionary named phoneBook which contains key-value pairs where each key represents a name and each value represents a phone number. The code then prints the value associated with the key "Pooja" using dictionary.

Example 3 :

phoneBook = {
    "Dolly" : "1234567890",
    "Anu" : "9876543210",
    "Avinash" : "21323422222",
    "Pooja" : "878975457"
}
print("Anu =",phoneBook["Anu"])

Output :

Anu = 9876543210

Example Explanation :

The code defines a dictionary named phoneBook which contains key-value pairs where each key represents a name and each value represents a phone number. The code then prints in a formatting way the value associated with the key "Anu" using a dictionary.

Example by using get() method :

Example 4 :

phoneBook = {
    "Dolly" : "1234567890",
    "Anu" : "9876543210",
    "Avinash" : "21323422222",
    "Pooja" : "878975457"
}
print(phoneBook.get("Avinash"))

Output :

21323422222

Example Explanation :

The code defines a dictionary named phoneBook which contains key-value pairs where each key represents a name and each value represents a phone number. We can print a specific keys values then you will use also get function one key and that key and that function will give a that specific key value.

Example 5 :

phoneBook = {
    "Dolly" : "1234567890",
    "Anu" : "9876543210",
    "Avinash" : "21323422222",
    "Pooja" : "878975457"
}
name = input("Enter name to find mob no :")
mobile = phoneBook.get(name)
print("Mobile Number :",mobile)

Output :

Enter name to find mob no :Pooja
Mobile Number : 878975457

Example Explanation :

The code defines a dictionary named phoneBook which contains key-value pairs where each key represents a name and each value represents a phone number. We can create one variable name and in that variable we can give a input from the user then in a next line we create a one variable is mobile and in a mobile we can pass that user input and in a next line we print that mobile number.

Example 6 :

fruitsNameToImage = {
    'Apple' : '🍎',
    'Graphs' : '🍇',
    'Banana' : '🍌',
    'Orange' : '🍊',
    'Cherry' : '🍒'
}
fruitKey = input("Enter fruit Name : ")
image =fruitsNameToImage.get(fruitKey)
print("{} Looks Like {}".format(fruitKey,image))

Output :

Enter fruit Name : Orange
Orange Looks Like 🍊

Example Explanation :

The code defines a dictionary name fruitsNameToImage which contains key-value pairs where each key represents a fruitsname and each value represents a fruitsemoji.

Example 7 :

courses ={
    "C" :"499",
    "C++" :"499",
    "Python" :"499",
    "DSA" :"999",
    "ICP" :"999",
    "ICGP" :"10,000"
}
print(courses.keys())

Output :

dict_keys(['C', 'C++', 'Python', 'DSA', 'ICP', 'ICGP'])

Example Explanation :

The code defines a dictionary named courses which contains key-value pairs where each key represents the name of a course and each value represents its price. The code then uses the keys() method of the courses dictionary to retrieve a list of all the keys in the dictionary.

Example 8 :

courses ={
    "C" :"499",
    "C++" :"499",
    "Python" :"499",
    "DSA" :"999",
    "ICP" :"999",
    "ICGP" :"10,000"
}
print(courses.values())

Output :

dict_values(['499', '499', '499', '999', '999', '10,000'])

Example Explanation :

The code defines a dictionary named courses which contains key-value pairs where each key represents the name of a course and each value represents its price. The code then uses the values() method of the courses dictionary to retrieve a list of all the values in the dictionary.

Adding New Key :

Syntax :

dictionary_name={
    key1:value1,
    key2:value2,
    key3:value3
}
dictionary_name["Key-name"]

Example :

courses ={
    "C" :"499",
    "C++" :"499",
    "Python" :"499",
    "DSA" :"999",
    "ICP" :"999",
    "ICGP" :"10,000"
}
print(courses)
courses["Java"] = "499"
print(courses)

Output :

{'C': '499', 'C++': '499', 'Python': '499', 'DSA': '999', 'ICP': '999', 'ICGP': '10,000'}
{'C': '499', 'C++': '499', 'Python': '499', 'DSA': '999', 'ICP': '999', 'ICGP': '10,000', 'Java': '499'}

Example Explanation :

The code defines a dictionary named courses which contains key-value pairs where each key represents the name of a course and each value represents its price. In the above example, we can add a new course and the new course is Java and print a directory in next time.

Update Key :

Syntax :

dictionary_name={
    key1:value1,
    key2:value2,
    key3:value3
}
dictionary_name["Key-name"] = "value"

Example :

courses ={
    "C" :"499",
    "C++" :"499",
    "Python" :"499",
    "DSA" :"999",
    "ICP" :"999",
    "ICGP" :"10,000"
}
print(courses)
courses["Python"] = "999"
print(courses)

Output :

{'C': '499', 'C++': '499', 'Python': '499', 'DSA': '999', 'ICP': '999', 'ICGP': '10,000'}
{'C': '499', 'C++': '499', 'Python': '999', 'DSA': '999', 'ICP': '999', 'ICGP': '10,000'}

Example Explanation :

The code defines a dictionary named courses which contains key-value pairs where each key represents the name of a course and each value represents its price. In the above example, we can update a Python value and print a directory in next line.

Remove key :

Syntax :

dictionary_name={
    key1:value1,
    key2:value2,
    key3:value3
}
dictionary_name.pop["Key-name"]

Example :

courses ={
    "C" :"499",
    "C++" :"499",
    "Python" :"499",
    "DSA" :"999",
    "ICP" :"999",
    "ICGP" :"10,000",
    'Java': '499'
}
print(courses)
courses.pop("Java")
print(courses)

Output :

{'C': '499', 'C++': '499', 'Python': '499', 'DSA': '999', 'ICP': '999', 'ICGP': '10,000', 'Java': '499'}
{'C': '499', 'C++': '499', 'Python': '499', 'DSA': '999', 'ICP': '999', 'ICGP': '10,000'}

Example Explanation :

The code defines a dictionary named courses which contains key-value pairs where each key represents the name of a course and each value represents its price. In the above example, we can use the pop() method and in a pop method we can pass one element and that element will be deleted.

Clear Dictionary :

Syntax :

dictionary_name={
    key1:value1,
    key2:value2,
    key3:value3
}
dictionary_name.clear()

Example :

courses ={
    "C" :"499",
    "C++" :"499",
    "Python" :"499",
    "DSA" :"999",
    "ICP" :"999",
    "ICGP" :"10,000",
    'Java': '499'
}
print(courses)
courses.clear()
print(courses)

Output

{'C': '499', 'C++': '499', 'Python': '499', 'DSA': '999', 'ICP': '999', 'ICGP': '10,000', 'Java': '499'}
{}

Example Explanation :

The code defines a dictionary named courses which contains key-value pairs where each key represents the name of a course and each value represents its price. In the above example, we can clear all dictionary then we will use clear() method. The clear() method is used to clear all the dictionary.

Dictionary in Python​

Adding New Key :​

Update Key :​

Remove key :​

Clear Dictionary :​

Dictionary in Python

Adding New Key :

Update Key :

Remove key :

Clear Dictionary :