1. INTRODUCTION TO PYTHON

2. FIRST PROGRAM IN PYTHON
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3. PYTHON IDENTIFIER
An identifier is a name given to entities like class, functions,
variables, etc. It helps to differentiate one entity from another.
Rules for writing identifiers:
I. Identifiers can be a combination of letters in lowercase (a to z) or
uppercase (A to Z) or digits (0 to 9) or an underscore _. Names
like myClass, var_1 and print_this_to_screen, _hrs all are valid
example.
II. An identifier cannot start with a digit. 1 variable is invalid,
but variable1 is perfectly fine.
III. Keywords cannot be used as identifiers.
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4. KEYWORDS
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 Every programming language has special reserved words,
or keywords, that have specific meanings and restrictions
around how they should be used.
Python keywords are the fundamental building blocks of any
Python program.
Python keywords are different from Python’s built-in functions
and types.

5. KEYWORDS
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 Every programming language has special reserved words,
or keywords, that have specific meanings and restrictions
around how they should be used.
Python keywords are the fundamental building blocks of any
Python program.
Python keywords are different from Python’s built-in functions
and types.

6. GETTING THE LIST OF KEYWORDS IN THE
PROMPT
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7. KEYWORDS
 Value Keywords: True, False, None.
 Operator Keywords: and, or, not, in, is.
 Import Keywords: import, from, as.
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8. OPERATOR KEYWORDS
Operator keyword : and will result into True only if both
the operands are True.
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A B A and B
True True True
True False False
False True False
False False False

9. OPERATOR KEYWORDS
Operator keyword : or will result into True only if any
operands are True.
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A B A and B
True True True
True False True
False True True
False False False

10. OPERATOR KEYWORDS
Operator keyword : not operator is used to invert the
truth value.
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A not A
True False
False True

11. IMPORT KEYWORD
 Import keyword :as is used to create an object while importing a
module. It means giving a different name(user-defined) to a module
while importing it.
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12. IMPORT KEYWORD
Import keyword : from…… import is used to import
specific attributes or functions into the current
namespace.
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13. LINES AND INDENTATION
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14. COMMENTS
Use of comments
• 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.
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15. COMMENT
In Python, we use the hash (#) symbol to start writing a comment.
It extends up to the newline character.
These triple quotes(‘’’ ‘’’) are generally used for multi-line strings.
But they can be used as multi-line comment as well.
Example : """This is also a
perfect example of
multi-line comments"""
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16. STATEMENT
 Instructions that a Python interpreter can execute are called
statements.
For example, a = 1 is an assignment statement.
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17. MULTILINE STATEMENT
 In Python, end of a statement is marked by a newline character. But we can make a
statement extend over multiple lines with the line continuation character ().
For example:
a = 1 + 2 + 3 +
4 + 5 + 6 +
7 + 8 + 9
 This is explicit line continuation. In Python, line continuation is implied inside
parentheses ( ), brackets [ ] and braces { }. For instance, we can implement the above
multi-line statement as
a = (1 + 2 + 3 +
4 + 5 + 6 +
7 + 8 + 9)
 Here, the surrounding parentheses ( ) do the line continuation implicitly. Same is the
case with [ ] and { }.
 We could also put multiple statements in a single line using semicolons, as follows
a = 1; b = 2; c = 3
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18. GETTING USER INPUT
• While Python provides us with two inbuilt functions to read the
input from the keyboard.
input ( prompt )
raw_input ( prompt )
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19. INPUT FUNCTION
 This function first takes the input from the user and then
evaluates the expression, which means Python automatically
identifies whether user entered a string or a number or list.
If the input provided is not correct then either syntax error or
exception is raised by python.
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20. WHAT ARE VARIABLES?
A variable is created the moment you first assign a
value to it.
Variables are containers for storing data values.
• Creating Python Variable :
Python has no command for declaring a variable.
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21. PYTHON VARIABLES - ASSIGN MULTIPLE
VALUES
Many Values to Multiple Variables:
Python allows you to assign values to multiple variables in one line.
One Value to Multiple Variables:
And you can assign the same value to multiple variables in one line.
Unpack a Collection
If you have a collection of values in a list, tuple etc. Python allows
you extract the values into variables. This is called unpacking.
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