The document discusses input and output functions in Python like input() and print(). It explains that the input() function allows taking user input, displays an optional prompt, and returns the input as a string. Examples show how input() works and how eval() can evaluate expressions. The document also covers implicit and explicit type conversions, noting that implicit conversions are automatic while explicit conversions use functions like int(), float(), and str() and may lose data.

1. Input and output
statements

2. Python provides numerous built-in functions that are readily
available to us at the Python prompt.
Some of the functions like input() and print() are widely used for
standard input and output operations respectively.
Let us see the input section first.
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3. Input statements
To allow flexibility, we might want to take the input from the
user. In Python, we have the input() function to allow this.
The syntax for input() is:
input([prompt])
where [prompt] is the string we wish to display on the
screen. It is optional.
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4. ● When input() function executes program flow will be stopped until
the user has given an input.
● The text or message display on the output screen to ask a user to
enter input value is optional i.e. the prompt, will be printed on the
screen is optional.
● Whatever you enter as input, input function convert it into a string. if
you enter an integer value still input() function convert it into a string.
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How the input function works in Python :

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Example 1
>>> num =
input('Enter a
number: ')
Enter a number: 10
>>> num
'10'
Example 2
x=input('enter your
name:')
enter your name:anu
>>> print(x)
anu

6. This same operation can be
performed using the eval()
function. But eval takes it further.
It can evaluate even expressions,
provided the input is a string.
Always use string as argument
for eval().
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>>> int('2+3')
Traceback (most recent call last):
File "<pyshell#1>", line 1, in <module>
int('2+3')
ValueError: invalid literal for int() with base
10: '2+3'
>>> eval('2+3')
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eval() for input

7. Data Type conversions
The process of converting the value of one data type
(integer, string, float, etc.) to another data type is called
type conversion. Python has two types of type
conversion.
1. Implicit Type Conversion
2. Explicit Type Conversion
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8. In Implicit type conversion, Python automatically converts
one data type to another data type. This process doesn't
need any user involvement.
Python promotes the conversion of the lower data type
(integer) to the higher data type (float) to avoid data loss.
See the Example 1 given below:
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Implicit Type Conversion

9. Example 1

10. Example 2
As we can see from the output, we got TypeError. Python is not able to use
Implicit Conversion in such conditions.
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11. In Explicit Type Conversion, users convert the data type of
an object to required data type.
This type of conversion is also called typecasting because
the user casts (changes) the data type of the objects.
Casting in python is therefore done using constructor
functions:
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Explicit Type Conversion

12. int() - constructs an integer
number from an integer literal, a
float literal (by rounding down
to the previous whole number),
or a string literal (providing the
string represents a whole
number)
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int()

13. float() - constructs a float
number from an integer
literal, a float literal or a
string literal (providing the
string represents a float or
an integer)
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float()

14. str() - constructs a string from a
wide variety of data types,
including strings, integer literals
and float literals.
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str()

15. Key Points to Remember
1. Type Conversion is the conversion of object from one data type to another data typ
2. Implicit Type Conversion is automatically performed by the Python interpreter.
3. Python avoids the loss of data in Implicit Type Conversion.
4. Explicit Type Conversion is also called Type Casting, the data types of objects are
converted using predefined functions by the user.
5. In Type Casting, loss of data may occur as we enforce the object to a specific data
type.
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