Python : Type Conversions

What is Type Conversion:

• Converting the one type of data/one data type into another type of data/another data type.

• In Java and .Net , Wrapper classes( wrapper classes contains some methods are available) support Type Conversion.

• In Python language, some predefined functions are there.

Why we need Type Conversion:

• After Reading the data into the Python application in the form of string format, Later we can convert string represented data into user required format by using type conversion.

Example1:

x= input("enter integer value: ")

print(x)

print(type(x))

y= int(x)

print(y)

print(type(y))

Output:

enter integer value: 12

12

<class 'str'>

12

<class 'int'>

Example2:

x= input("enter float value: ")

print(x)

print(type(x))

y= float(x)

print(y)

print(type(y))

Output:

enter float value: 3.7

3.7

<class 'str'>

3.7

<class 'float'>

Example3:

x= input("enter bool value: ")

print(x)

print(type(x))

y= bool(x)

print(y)

print(type(y))

Output:

enter bool value: True

True

<class 'str'>

True

<class 'bool'>

Example4:

x= input("enter complex value: ")

print(x)

print(type(x))

y= complex(x)

print(y)

print(type(y))

Output:

enter complex value: 3+4j

3+4j

<class 'str'>

(3+4j)

<class 'complex'>

Note:

• Reading the data from the keyboard by using pre-defined function called input in python.

• python 2.x -----> input, raw_input. ---> type conversion is implicitly done.

• python 3.x ----> input, ---->type conversion is explicitly,programmer can be done.

• The input function read the data from the keyboard in the form of string format only.

Limitations with respect in type conversion:

Example1:

x= input("enter integer value: ")

print(x)

i=int(x)

y=input("enter integer value: ")

print(y)

j=int(y)

print(i+j)

Output 1:

enter integer value: 4

4

enter integer value: 5

5

9

Output 2:

enter integer value: 6

6

enter integer value: 2.1

2.1

Traceback (most recent call last):

  File "E:/python_practice/type conversons.py", line 6, in <module>

    j=int(y)

ValueError: invalid literal for int() with base 10: '2.1'

Example 2:

x= input("enter float value: ")

print(x)

i=float(x)

y=input("enter float value: ")

print(y)

j=float(y)

print(i+j)

Output 1:

enter float value: 2.3

2.3

enter float value: 4.7

4.7

7.0

Output 2:

enter float value: 2.6

2.6

enter float value: 2

2

4.6

Output 3:

enter float value: 4

4

enter float value: 2

2

6.0