Ivy Mar 20, 2020 No Comments
Data types are the building blocks of every programming language. Any variable that stores a value contains some data which can be Boolean, string, number, etc. We talk in terms of classes and objects in Python. Data types are classes and the variables are objects. We can operate a variable based on what kind of data it has stored. In this article, we are going to explain all the data types available in Python and how we operate on them.
First of all, let us understand the rules to assign a variable.
Python has 5 Standard data types which are listed below.
When we store a numeric value in a variable, it automatically is classified as a numeric Python data type. There are 3 different numeric data types which are explained below.
1) Int (plain integers) – Any positive or negative whole number is called an integer and given int data type.
2) Float (floating point real values) – Real numbers with decimal values are called float.
3) Complex numbers – This type is used rarely in Python. A complex number is represented by X + iY where X and Y are floats and i is the square root of -1 (the result of which is an imaginary number)
Please note – Python 2 has two integer types – integer and a long integer. There is no ‘long integer’ in Python 3 anymore.
Now let us see how to work on this. We are defining three variables of different data types. In Python, we do not have to explicitly mention data type during the assignment of a variable. Applying the ‘Type’ function on a variable helps us identify the data type. We have used print command to get the result.
standard = 10 # integer car_loan_amount = 10000.90 # float import cmath complex_number = complex(10,20) print(type(standard)) print(type(car_loan_amount)) print(type(complex_number)) print(complex_number.real) print(complex_number.imag)
There are 3 data types which comprise of a sequence of characters called string, or a sequence of mixed data types called a list or tuple.
String –
A series of characters within a single, double or triple quotes is called a string. There is no character data type in Python like other languages. Let us see how to define a string variable along with its data type. In the below list of codes
school_name = 'DPS' # str print(type(school_name)) string_text = '''DPS is a very famous school''' # str print(type(string_text))
#1 - length len(string_text) len(school_name) #2 - Accessing the 6th element in the string string_text[5] #2 - Accessing a sequence of elements string_text[6:10] #3 - Reversing the string school_name[::-1] string_text[::-1] #4 - String concatenation string_text + " " + school_name
List –
It is a compound data type. We can store various data types as elements in a list. To explain in other words, a list can consist of an integer, a string, as well as another list inside it. Every element in a list can be accessed with its index which starts with 0. A list is mutable. That is we can delete and modify its elements. Let us see how we can create a list.
#creating a list list1 = [1,2,'a','b','world cup'] #creating a nested list that is a list within a list list2 = [1,2,'a','b','world cup', [1,2,'a','b','world cup']]
#getting the element at the second index print(list1[2]) #getting a sequence of elements from 1st to 3rd index can be made using [1:4] which follows [inclusion : exclusion] rule print(list1[1:4])
#append function
list1.append('cricket')
print(list1)
#appending another list
list1.append(list2)
print(list1)
(list1.extend(list2)) print(list1)
list1.index('a')
list1.count('a')
Insert takes in two arguments: insert(index, object) This method places the object at the index supplied.
list1.insert(2,'inserted') print(list1)
list1.reverse() print(list1)
Python provides an immutable compound data type called Tuple. Similar to a list, a tuple can store elements of various data types but we can not edit it after creation. A few ways in which we can create a tuple are:
#create an empty tuple tuple() t() #create a tuple with 4 elements t = (1,2,3,4) print(t)
Some operations we can perform on a tuple are finding max, min, count, index, etc. to show a few methods. Let us see their commands.
tup = (10,20,30,30,20,10,40,40,40,50,100) print(tup.count(30)) print(tup.index(40)) print(min(tup)) print(max(tup))
Another compound data type in Python is a dictionary. In this, we can save elements in a combination of key and value pairs and we can use this as a map. The syntax of a dictionary is { key1: value1, key2: value2, …. } . The command to create a dictionary is provided.
dictionary1 = { 'name':'ivy' , 'class':'python', 'month':'march', 'year':2020}
dictionary1.keys()
We use method values().
dictionary1.values()
The Update method will add a new Key value pair if the key is not found. Else, it updates the value of the existing key.
dictionary1.update({'batch':100})
print(dictionary1)
set1 = set([1,2,3,4]) type(set1)
#1 - adding set1.add(5) set1 #2 - removing set1.remove(5) #3 - subset/superset gives a true or false output set1 = set([1,2,3,4,5,6,7,8,9]) set2 = set([3,6,9]) set1.issubset(set2) set1.issuperset(set2) #4 set operations set1.union(set2) set1.intersection(set2) set1.difference(set2)
All the various data types which one can require while working in Python have been explained. Please do let us know if there is any doubt regarding any command or data type. Next, we are going to discuss Loops in Python. Stay Tuned.!!
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