We can create different types of variables as per our requirements. Let's see each one by one.
Number
A number is a data type to store numeric values. The object for the number will be created when we assign a value to the variable. In Python3, we can use the following three data types to store numeric values.
#1 int
#2 float
#3 complex
Integer variable
The int is a data type that returns integer type values (signed integers). They are also called ints or integers. The integer value can be positive or negetive without a decimal point.
Example:
# create integer variable age = 25 print(age) # 25 print(type(age)) #
Note: We used the built-in Python method type() to check the variable type.
Float variable
Floats are the values with the decimal point dividing the integer and the fractional parts of the number. User float data type to store decimal values.
Example:
# create float variable salary = 3000.0 print(salary) # 3000.0 print(type(salary)) #
In the above example, the variable salary assigned to value 3000.0, which is a float value.
Float variable
The complex is the numbers that come with the real and imaginary part. A complex number is in the form of a + bj, where a and b contain integers or floating-point values.
Example:
a = 3 + 5j print(a) # (3+5j) print(type(a)) #
String variable
In Python, a string is a set of characters represented in quotation marks. Python allows us to define a string in either pair of single or double quotation marks. For example, to store a person's name we can use a string type.
To retrieve a piece of string from a given string, we can use to slice operator [ ] or [ : ]. Slicing provides us the subset of a string with an index starting from index 0 to index end -1.
To concatenate the string, we can use the addition (+) operator.
Example:
# create a variable of type string str = 'python' # prints complete string print(str) # python # prints first character of the string print(str[0]) # p # prints characters starting from 2nd to 5th print(str[2:5]) # tho # length of string print(len(str)) # 6 # concatenate string print(str + "Test") # pythonTest
List type variable
If we want to represent a group of elements (or value) as a single entity, we should go for the list variable type. For example, we can use them to store student names. In the list, the insertion order of elements is preserved. That means, in which order elements are inserted in the list, the order will be intact.
The list can be accessed in two ways, either positive or negative index. The list has the following characteristics:
1. In the list insertion order of elements is preserved.
2. Heterogeneous (all types of data types int, float, string) elements are allowed.
3. Duplicates elements are permitted.
4. The list is mutable(can change).
5. Growable in nature means based on our requirement, we can increase or decrease the list's size.
6. List elements should be enclosed within square brackets [ ].
Example:
# create list ls = ['John', 10, 20, 'Tom', 50, 10.5] # print entire list print(ls) # ['John', 10, 20, 'Tom', 50, 10.5] # accessing 1st element of a list print(ls[0]) # 'John' # accessing last element of a list print(ls[-1]) # 10.5 # access chunks of list data print(ls[1:3]) # [10,20] # modifying first element of a list ls[0] = 'Jenny' print(ls[0]) # 'Jenny' # add one more elements to list ls.append(100) print(ls) # ['Jenny', 10, 20, 'Tom', 50, 10.5, 100]
