The document provides an introduction to the Python programming language. It discusses that Python was created by Guido Van Rossum in 1991 and was named after the Monty Python comedy troupe. Python is an open source, interpreted language that can be used for both procedural and object-oriented programming. It has a simple syntax and supports features like graphical user interfaces, integration with other languages, and is used widely in applications like web development, artificial intelligence, and data science. The document also covers Python concepts like variables, data types, operators, input/output and comments.

1. Introduction to
Python
Jincy M Nelson
THRS

2. PYTHON
• A programming language developed
by Guido Van Rossum in feb-1991.
• Named after a comedy show namely
‘Monty Python’s Flying Circus’.
• It is based on ABC language.
• It is an open source language.

3. Features of Python
 It is an pen source, so it can be
modified and redistributed.
 Uses a few keywords and clear
,simply English like structure.
 Can run on variety of platforms.
 Support procedure oriented as well as
object oriented programming.

4. Features of Python
 It support Graphical user interface.
 It is compatible with C,C++ languages
etc.
 Used in game development, data
base application, web application ,
Artificial Intelligence.
 Lesser time required to learn Pyhton
as it has simple and concise code.

5. Features of Python
Distinguish between input, output and
error message by different colour
code.
Has large set of libraries with various
module functions.
Has automatic memory management.
Provide interface to all major
databases.

6. Applications of Python
• Amazon uses python to analyse customer’s
buying habits and search patterns.
• Facebook uses python to process images.
• Google uses python in search system.
• NASA uses python for scientific
programming tasks.
• Python is used in AI systems.

7. Python Character Set:
• A set of Valid characters that a language can recognize.
• A character set includes:
Letters : A-Z , a-z.
Digits : 0-9
Special Symbols :Space + -*/**(){}[]//!= ==<,>.’’ “”;:%!
White spaces : Blank space ,tabs carriage return ,new
line , form feed.
Other Characters : process all ASCII

8. Variable
• Has a name
• Capable of storing values of certain
data type.
• Provide temporary storage.

9. Variable naming conventions
• Variable names are case sensitive.
• Keywords or words with special meanings
should not be used as variables.
• Variable names should be short and
meaningful.
• All variable names should begin with a letter
or underscore(_).
• Variable names may contain numbers,
underscore,.
• no space or special character allowed

10. Keywords
• Keywords are the words that convey a
special meaning to the language
compiler/interpreter.
• These are reserved for special
purpose.
• Must not be used as normal variables.
• Eg: True, False , if, return , try, elif ,
and ,while, None ,with ,range ,break ,
for ,in ,or

11. Data Types
• Data types states the way the values of
that type are stored .
• The operations can be done on that
type and the range for that type.
• Different types of data requires different
amount of memory for storage.
• Data can be manipulated through
specific data types.

12. Standard Data Types
• Numbers
• String
• List
• Tuple
• Dictionary

13. Number
• Number data type is used to store
numerical values.
• Python support three numerical data
types.
• Integer: eg a=2
• Float: eg: a=2.766
• Complex Numbers: a=17+9b

14. String
• An order of set of characters closed
in a single or double quotation marks.
• Eg: str1=‘Hello’
• wrd=“Hello”

15. List
• List is a collection of comma separated
values within square bracket.
• Values in the list can be modified.
• The values in the list are called
elements.
• It is mutable.
• Elements in the list need not be of
same type.

16. Eg:
• List1=[1,56,84,5]
• List2=[45,98,48,65,0,23]
• List3=[‘anna’,’aby’,’riya’,’diya’]

17. Tuple
• A tuple is a sequence of comma
separated values . Values in tuple
cannot be changed.
• It is immutable.
• The values in the tuple are called as
elements.
• Elements in the list need not be of
same type.

18. Eg:
tup1=(‘Sunday’,’Monday’,10,20)
tup2=(10,20,30)
tup3=(‘a’,’b’,’c’,’d’)

19. Dictionary
• An unordered collection of items where
each item is a key: value pair
• Each key is separated from its value
by a colon (:) .
• The entire dictionary is enclosed within
curly braces {}.
• Keys are unique within dictionary while
the values may not be.

20. • Eg:
• Dic1={‘R’:RAINY, ‘S’:SUMMER, ‘W’:
WINTER, ‘A’=AUTUMN}

21. Boolean data type
• The Boolean data type is either TRUE
or FALSE
• In python, Boolean variables are
defined by either True or False.
• The first letter of True and False must
be in upper case . Lower case returns
error

22. Eg:
>>> a=True
>>> type(a)
<class 'bool'>
>>> a=True
>>> b=False
>>> a or b
True
>>> a and b
False
>>> not a
False
>>> a==b
False
>>> a!=b
True
>>>

23. Data Type Conversion
• The process of converting the value of
one data type to another data type is
called type conversion.
• There are two types of conversion
• Implicit type conversion
• Explicit type conversion

24. Implicit type conversion
• In this python automatically convert
one data type to another.
• This process doesn’t need any user
involvement.

25. Program:
a=50
b=45.5
print('Type of a:',type(a))
print('Type of b:',type(b))
c=a+b
print('Type of c:',type(c))
Output:
Type of a: <class 'int'>
Type of b: <class 'float'>
Type of c: <class 'float'>

26. Explicit type conversion
• User convert the data type of an object
to the required data type.
• We use predefined functions like int(),
float(),complex(), bool(), str(), tuple(),
list() ,dict() etc to perform explicit type
conversion.
• This type conversion is also known as
type casting.

27. Input
a=100
b=20.50
c='567'
print('Variable a converted into string:',str(a))
print('Variable a converted into float:',float(a))
print('Variable b converted into integer:',int(b))
print('Variable b converted into string:',str(b))
print('Variable c converted into integer:',int(c))
print('Variable c converted into float:',float(c))
print('Variable a converted into list:',list(c))
OUTPUT
Variable a converted into string: 100
Variable a converted into float: 100.0
Variable b converted into integer: 20
Variable b converted into string: 20.5
Variable c converted into integer: 567
Variable c converted into float: 567.0
Variable a converted into list: ['5', '6', '7']

29. Operators
• Are special symbols which represent
computation.
• Values or variables are called
oparands .
• The operator is applied on operands,
thus form expression.

31. Precedence of Arithmetic
operators

32. Relational Operators

37. Assigning value to variable

38. User input
• The values inserted by the user while executing a program are
fetched and stored in the variable using the input() function.

39. User output
• The print statement is used to display
the value of a variable.
• If an expression is given with the print
statement ,it first evaluate the
expression and then print it.
• To print more than one item on a
single line comma (,) can be used.

40. User output

41. comments
• A comment in Python starts with the hash
character, # , and extends to the end of the
physical line.
• Comments can be used to explain Python
code.
• Comments can be used to make the code
more readable.
• Comments can be used to prevent
execution when testing code.

42. Creating a Comment
• Comments starts with a #, and Python will ignore
them:
• Example
• #This is a comment
print("Hello, World!")
• Comments can be placed at the end of a line, and
Python will ignore the rest of the line:
• Example
• print("Hello, World!") #This is a comment
•

43. • A comment does not have to be text
that explains the code, it can also be
used to prevent Python from executing
code:
• Example
• #print("Hello, World!")
print("Cheers, Mate!")

44. Multi Line Comments
• Python does not really have a syntax
for multi line comments.
• To add a multiline comment you could
insert a # for each line:
• Example
• #This is a comment
#written in
#more than just one line
print("Hello, World!")

45. • Or, not quite as intended, you can use a
multiline string.
• Since Python will ignore string literals that are
not assigned to a variable, you can add a
multiline string (triple quotes) in your code, and
place your comment inside it:
• Example
• """
This is a comment
written in
more than just one line
"""
print("Hello, World!")

46. Indentation In Python
• Indentation refers to the spaces at the
beginning of a code line.
• Python uses indentation to indicate a block
of code.
• Python will give you an error if you skip the
indentation:
• You have to use the same number of
spaces in the same block of code, otherwise
Python will give you an error: