2. History
Python was considered in the late 1980s and its implementation was
started in December 1989 by Guido van Rossum at CWI in the Netherlands
as a successor to the ABC programming language capable of exception
handling and interfacing with the Amoeba operating system.
Van Rossum is Python's principal author, and his continuing central role in
deciding the direction of Python is reflected in the title given to him by the
Python community.
3. Introduction
Python is a widely used general-purpose, high-level programming
language.
Its design philosophy emphasizes code readability, and its syntax allows
programmers to express concepts in fewer lines of code than would be
possible in languages such as C++ or Java.
The language provides constructs intended to enable clear programs on
both a small and large scale.
4. Support in Python
Python supports multiple programming paradigms, including object-oriented,
imperative and functional programming or procedural styles.
It features a dynamic type system and automatic memory management and has a
large and comprehensive standard library.
Python interpreters are available for installation on many operating systems, allowing
Python code execution on a wide variety of systems.
Python is a multi-paradigm programming language: object-oriented programming
and structured programming are fully supported, and there are a number of language
features which support functional programming and aspect-oriented programming
5. Brief History
Invented in the Netherlands, early 90s by Guido van Rossum
Named after Monty Python
Open sourced from the beginning, managed by Python Software
Foundation
Considered a scripting language, but is much more
Scalable, object oriented and functional from the beginning
Used by Google from the beginning
6. Features of Python
Simple
Easy to Learn
Free and Open Source
High-level Language
Portable
Interpreted
Object Oriented
Extensible
Embeddable
7. Python Installation Steps
Step-1: Browse the link to download the python latest version
https://www.python.org/
Step-2: Install it by double click and choose the system path to
install
Step-3: Finally , Click the Finish button .
Python Screen
8. Simple Program
Python is a very simple language, and has a very straightforward
syntax. It encourages programmers to program without boilerplate
(prepared) code. The simplest directive in Python is the "print"
directive - it simply prints out a line (and also includes a newline,
unlike in C).
There are two major Python versions, Python 2 and Python 3.
Python 2 and 3 are quite different.
For example, one difference between Python 2 and 3 is
the print statement. In Python 2, the "print" statement is not a
function, and therefore it is invoked without parentheses. However,
in Python 3, it is a function, and must be invoked with parentheses.
9. Basic Syntax
Basic syntax of a python program is too simple than other languages.
Let's take an example, here the following program prints "Hello Python, I
am Python Basic Syntax" as output:
Coding:
Output:
10. Read User Input from Keyboard in Python
To get input from user in python, you have to use input() function. You can get any type of input using this input()
function in python, you have only to place the type before the statement to get the desired type of input using the
input() statement in python.
Get Integer Input from User
# Python Program - Get Integer Input from User
while True:
print("Enter '0' for exit.")
val = int(input("Enter any number: "))
if val == 0:
break
else:
print("You have just entered:", val)
print()
12. Get Floating-point Input from User
This python program shows how to get floating-point input from user in
python:
# Python Program - Get Floating-point Input from User
while True:
print("Enter '0' for exit.")
val = float(input("Enter any number: "))
if val == 0:
break
else:
print("You have just entered:", val)
print()
14. Get String Input from User
Here is another program shows how to get string input from user in python:
# Python Program - Get String Input from User
while True:
print("Enter 'x' for exit.")
val = raw_input("Enter any string: ")
if val == 'x':
break
else:
print("You have just entered:", val)
print()
16. Complete Version of Getting Input from
User
Here is the complete version of getting input from user in python:
# Python Program - Get Input from User - Complete Version
while True:
print("Enter '0' for exit.")
val = int(input("Enter any Number: "))
flt = float(input("Enter any Floating-point Number: "))
strg = raw_input("Enter any String: ")
if val == 0:
break
else:
print "Integer:",val
print "Floating-point:",flt
print "String:",strg
18. Variables in Python
Variables in Python, are the reserved memory locations to store the values
in a Python program.
It means that, whenever you are creating a variable in Python
programming, you are reserving some space in the memory for that
variable.
Based on variable's data type, python interpreter allocates the memory and
decides what can be stored in the reserved memory. Here is an example
assigning values to the variables in Python.,
20. Python Variables - Example Program
# Python Variables - Example Program
m=54
n=45
r=0
r=m+n
print "sum = ", r
r=m-n
print "Subtract = ", r
r=m*n
print "Multiply = ", r
r=m/n
print "Divide = ", r
22. Data types in Python
Basically data type represents the type of value and determines how the value can be used in a
python program. Since all the data values are encapsulated in relevant object classes.
Everything in Python, is simply an object and every object has an identity, a type and a value.
There are following five standard data types available in Python programming:
I. Numbers type
II. Strings type
III. List type
IV. Tuple type
V. Dictionary type
23. Number type
Number data types store numeric values.
Number objects are created when you assign a value to them.
For example −
var1 = 1
var2 = 10
You can also delete the reference to a number object by using the del statement.
The syntax of the del statement is −
del var1[,var2[,var3[....,varN]]]].
You can delete a single object or multiple objects by using the del statement.
For example −
del var
del var_a, var_b
24. Python supports four different numerical
types
int (signed integers)
long (long integers, they can also be represented in octal and hexadecimal)
float (floating point real values)
complex (complex numbers)
25. Python Number Example
# Python Number Data Type - Example Program
num1 = 10
num2 = 20
print("num1 = ", num1, " and num2 = ", num2);
26. use of del keyword in python
# Python Number Data Type - Example Program
num1 = 10
num2 = 20
print "num1 = ", num1, " and num2 = ", num2
del num1, num2
print "num1 = ", num1, " and num2 = ", num2
28. String Data Type
Strings in Python, are contiguous set of characters between quotation marks.
You are free to use either pairs of single or double quotes in Python programming.
Here is an example of string.
Strings in Python are identified as a contiguous set of characters represented in the
quotation marks. Python allows for either pairs of single or double quotes. Subsets of
strings can be taken using the slice operator ([ ] and [:] ) with indexes starting at 0 in
the beginning of the string and working their way from -1 at the end.
The plus (+) sign is the string concatenation operator and the asterisk (*) is the
repetition operator.
29. String Example
# Python Strings - Example Program
str1 = 'Hello Python'
str2 = "This is Python Strings Tutorial"
print(str1, "n", str2);
30. String Examples
# Python String - Example Program
str = 'Hello Python'
print (str) # this will print the complete string
print (str[0]) # this will print the first character of the string
print (str[2:8]) # this will print the characters starting from 3rd to 8th
print (str[3:]) # this will print the string starting from the 4th character
print (str * 3) # this will print the string three times
print (str + "String") # this will print the concatenated string
32. List Data type
A list in Python, contains items separated by commas and enclosed within
square brackets.
A list basically contains items separated by commas and enclosed within
the square brackets [ ]. Items in the list needn't be of the same type.
Examples:
list1 = ['computer', 'programming', 1957, 2070, 3242];
list2 = [1, 2, 3, 4, 5];
list3 = ["a", "b", "c", "d", "e"];
33. Python List Example
# Python Lists - Example Program
list1 = ["python", "list", 1952, 2323, 432]
list2 = ["this", "is", "another", "list"]
print list1 # this will print the complete list
print list1[1:4] # this will print the elements starting from 2nd till 4th
print list1[1:] # this will print the elements starting from the 2nd element
print list1[0] # this wil print the first element of the list
print list1 * 2 # this will print the list two times
print list1 + list2 # this will print the concatenated list
35. Tuples Data Type
A tuple is another sequence data type that is similar to the list. A tuple consists of a
number of values separated by commas. Unlike lists, however, tuples are enclosed
within parentheses.
The main differences between lists and tuples are: Lists are enclosed in brackets ( [ ] )
and their elements and size can be changed, while tuples are enclosed in parentheses (
( ) ) and cannot be updated. Tuples can be thought of as read-only lists.
Examples:
tuple1 = ("python", "tuple", 1952, 2323, 432);
tuple2 = (1, 2, 3, 4, 5);
tuple3 = ("a", "b", "c", "d", "e");
36. Tuple Example
# Python Tuple - Example Program
tuple1 = ("python", "tuple", 1952, 2323, 432);
print tuple1 # this will print the complete tuple
print tuple1[1:4] # this will print the elements starting from 2nd till 4th
print tuple1[1:] # this will print the elements starting from the 2nd
element
print tuple1[0] # this wil print the first element of the tuple
print tuple1 * 2 # this will print the tuple two times
38. Dictionary Data type
Python's dictionaries are kind of hash table type. They work like
associative arrays or hashes found in Perl and consist of key-value
pairs.
A dictionary key can be almost any Python type, but are usually
numbers or strings. Values, on the other hand, can be any arbitrary
Python object.
Dictionaries are enclosed by curly braces ({ }) and values can be
assigned and accessed using square braces ([]).
39. Dictionary Example
# Python Dictionary - Example Program
dictionary1 = {}
dictionary1['one'] = "This is one"
dictionary1[2] = "This is two"
smalldictionary = {'name': 'Devraj','id':9388, 'branch': 'cs'}
print dictionary1[2] # this will print the values for 2 key
print dictionary1['one'] # this will print the value for 'one' key
print smalldictionary # this will print the complete dictionary
print smalldictionary.keys() # this will print all the keys
print smalldictionary.values() # this will print all the values
41. Determine Variable's Type in Python
You can use the function type() available in Python, to determine the type of variable in Python.
Here is an example showing the use of type() function in determining variable's type in Python
# Python Data Types - Example Program
i=10
print(type(i))
f=324.423
print(type(f))
b=True
print(type(b))
str="Python Data Types"
print(type(str))
43. Operators in Python
Operators in Python, are used to perform mathematical and logical
operations.
There are the following types of operators available in Python:
Arithmetic Operators
Logical Operators
Comparison (Relational) Operators
Assignment Operators
Bitwise Operators
Membership Operators
Identity Operators
44. Python Arithmetic Operators
# Python Operators - Python Arithmetic Operators - Example
Program
num1 = 23
num2 = 10
res = 0
print("If num1 = 23 and num2 = 10. Then,");
res = num1 + num2
print("num1 + num2 = ", res)
res = num1 - num2
print("num1 - num2 = ", res)
res = num1 * num2
print("num1 * num2 = ", res)
res = num1 / num2
print("num1 / num2 = ", res)
res = num1 % num2
print("num1 % num2 = ", res)
#changing the values of num1 and num2
num1 = 2
num2 = 3
print("nIf num1 = 2 and num2 = 3. Then,");
res = num1 ** num2
print("num1 ** num2 = ", res)
#again changing the values of num1 and num2
num1 = 10
num2 = 5
print("nIf num1 = 10 and num2 = 5. Then,");
res = num1 // num2
print("num1 // num2 = ", res)
46. Comparison operators in Python
Operator Meaning
==
This operator checks if the value of the two operands are equal or not. If equal, then
the condition becomes true, otherwise false
!=
This operator checks if the value of the two operands are equal or not. If not equal,
then the condition becomes true, otherwise false
>
This operator checks if the value of the left operand is greater than the value of the
right operand or not. If yes, then the condition becomes true, otherwise false
<
This operator checks if the value of the left operand is less than the value of the right
operand or not. If yes, then the condition becomes true, otherwise false
>=
This operator checks if the value of the left operand is greater than or equal to the
value of the right operand or not. If yes, then the condition becomes true
<=
This operator checks if the value of the left operand is less than or equal to the value
of the right operand or not. If yes, then the condition becomes true
47. Comparison Operators - Example Program
# Python Operators - Comparison Operators - Example
Program
num1 = 23
num2 = 10
res = 0
print "If num1 = 23 and num2 = 10. Then,";
if num1 == num2 :
print "num1 is equal to num2";
else:
print "num1 is not equal to num2";
if num1 != num2 :
print "num1 is not equal to num2";
else:
print "num1 is equal to num2";
if num1 < num2 :
print "num1 is less than num2";
else:
print "num1 is not less than num2";
if num1 > num2 :
print "num1 is greater than num2";
else:
print "num1 is not greater than num2";
if num1 <= num2 :
print "num1 is either less than or equal to num2";
else:
print "num1 is neither less than or equal to num2";
if num1 >= num2 :
print "num1 is either greater than or equal to num2";
else:
print "num1 is neither greater than or equal to num2";
# changing the values of num1 and num2
num1 = 40
num2 = 40
print"nIf num1 = 40 and num2 = 40. Then,";
if num1 <= num2 :
print "num1 is either less than or equal to num2";
else:
print "num1 is neither less than or equal to num2";
if num1 >= num2 :
print "num1 is either greater than or equal to num2";
else:
print "num1 is neither greater than or equal to num2";
49. Python Assignment Operators - Example
Program
num1 = 25
num2 = 10
res = 0
print "If num1 = 25 and num2 = 10. Then,";
res = num1 + num2
print "num1 + num2 = ", res;
res += num1
print "res + num1 = ", res;
res -= num1
print "res - num1 = ", res;
res *= num1
print "res * num = ", res;
res /= num1
print "res / num1 = ", res;
# changing the values of res
res = 2
res %= num1
print "res % num1 = ", res;
res **= num1
print "res ** num1 = ", res;
res //= num1
print "res // num1 = ", res;
51. Bitwise operators
# Python Operators - Python Bitwise Operators - Example Program
num1 = 60
num2 = 13
res = 0
print "If num1 = 60 and num2 = 13. Then,";
res = num1 & num2;
print "num1 & num2 = ", res;
res = num1 | num2;
print "num1 | num2 = ", res;
res = num1 ^ num2;
print "num1 ^ num2 = ", res;
res = ~num1;
print "~num1 = ", res;
res = ~num2;
print "~num2 = ", res;
res = num1 << 2;
print "num1 << 2 = ", res;
res = num2 << 2;
print "num2 << 2 = ", res;
res = num1 >> 2;
print "num1 >> 2 = ", res;
res = num2 >> 2;
print "num2 >> 2 = ", res;
# changing the values of num1 and num2
num1 = 60
num2 = 0
print "nIf num1 = 60 and num2 = 0. Then,";
res = num1 & num2;
print "num1 & num2 = ", res;
res = num1 | num2;
print "num1 | num2 = ", res;
53. Logical operators
# Python Operators - Python Logical Operators - Example Program
num1 = 100
num2 = 200
res = 0
print("If num1 = 100 and num2 = 200. Then,");
if(num1 and num2):
print("Both num1 and num2 are true");
else:
print("Either num1 or num2 is not true, or both are not true");
if(num1 or num2):
print("Either num1 or num2 is true, or both are true");
else:
print("Neither num1 nor num2 is true");
# changing the values of num1 and num2
num1 = 5
num2 = 0
print("nIf num1 = 5 and num2 = 0. Then,");
if(num1 and num2):
print("Both num1 and num2 are true");
else:
print("Neither num1 nor num2 is true");
if(num1 or num2):
print("Either num1 or num2 is true, or both are
true");
else:
print("Neither num1 nor num2 is true");
if not(num1 and num2):
print("Neither num1 nor num2 is true");
else:
print("Both num1 and num2 are true");
![Number type
Number data types store numeric values.
Number objects are created when you assign a value to them.
For example −
var1 = 1
var2 = 10
You can also delete the reference to a number object by using the del statement.
The syntax of the del statement is −
del var1[,var2[,var3[....,varN]]]].
You can delete a single object or multiple objects by using the del statement.
For example −
del var
del var_a, var_b](https://image.slidesharecdn.com/1-introduction1-250401061226-93cedabc/85/1-Introduction-to-Python-features-of-python-history-of-python-1-pptx-23-320.jpg)
![String Data Type
Strings in Python, are contiguous set of characters between quotation marks.
You are free to use either pairs of single or double quotes in Python programming.
Here is an example of string.
Strings in Python are identified as a contiguous set of characters represented in the
quotation marks. Python allows for either pairs of single or double quotes. Subsets of
strings can be taken using the slice operator ([ ] and [:] ) with indexes starting at 0 in
the beginning of the string and working their way from -1 at the end.
The plus (+) sign is the string concatenation operator and the asterisk (*) is the
repetition operator.](https://image.slidesharecdn.com/1-introduction1-250401061226-93cedabc/85/1-Introduction-to-Python-features-of-python-history-of-python-1-pptx-28-320.jpg)
![String Examples
# Python String - Example Program
str = 'Hello Python'
print (str) # this will print the complete string
print (str[0]) # this will print the first character of the string
print (str[2:8]) # this will print the characters starting from 3rd to 8th
print (str[3:]) # this will print the string starting from the 4th character
print (str * 3) # this will print the string three times
print (str + "String") # this will print the concatenated string](https://image.slidesharecdn.com/1-introduction1-250401061226-93cedabc/85/1-Introduction-to-Python-features-of-python-history-of-python-1-pptx-30-320.jpg)
![List Data type
A list in Python, contains items separated by commas and enclosed within
square brackets.
A list basically contains items separated by commas and enclosed within
the square brackets [ ]. Items in the list needn't be of the same type.
Examples:
list1 = ['computer', 'programming', 1957, 2070, 3242];
list2 = [1, 2, 3, 4, 5];
list3 = ["a", "b", "c", "d", "e"];](https://image.slidesharecdn.com/1-introduction1-250401061226-93cedabc/85/1-Introduction-to-Python-features-of-python-history-of-python-1-pptx-32-320.jpg)
![Python List Example
# Python Lists - Example Program
list1 = ["python", "list", 1952, 2323, 432]
list2 = ["this", "is", "another", "list"]
print list1 # this will print the complete list
print list1[1:4] # this will print the elements starting from 2nd till 4th
print list1[1:] # this will print the elements starting from the 2nd element
print list1[0] # this wil print the first element of the list
print list1 * 2 # this will print the list two times
print list1 + list2 # this will print the concatenated list](https://image.slidesharecdn.com/1-introduction1-250401061226-93cedabc/85/1-Introduction-to-Python-features-of-python-history-of-python-1-pptx-33-320.jpg)
![Tuples Data Type
A tuple is another sequence data type that is similar to the list. A tuple consists of a
number of values separated by commas. Unlike lists, however, tuples are enclosed
within parentheses.
The main differences between lists and tuples are: Lists are enclosed in brackets ( [ ] )
and their elements and size can be changed, while tuples are enclosed in parentheses (
( ) ) and cannot be updated. Tuples can be thought of as read-only lists.
Examples:
tuple1 = ("python", "tuple", 1952, 2323, 432);
tuple2 = (1, 2, 3, 4, 5);
tuple3 = ("a", "b", "c", "d", "e");](https://image.slidesharecdn.com/1-introduction1-250401061226-93cedabc/85/1-Introduction-to-Python-features-of-python-history-of-python-1-pptx-35-320.jpg)
![Tuple Example
# Python Tuple - Example Program
tuple1 = ("python", "tuple", 1952, 2323, 432);
print tuple1 # this will print the complete tuple
print tuple1[1:4] # this will print the elements starting from 2nd till 4th
print tuple1[1:] # this will print the elements starting from the 2nd
element
print tuple1[0] # this wil print the first element of the tuple
print tuple1 * 2 # this will print the tuple two times](https://image.slidesharecdn.com/1-introduction1-250401061226-93cedabc/85/1-Introduction-to-Python-features-of-python-history-of-python-1-pptx-36-320.jpg)
![Dictionary Data type
Python's dictionaries are kind of hash table type. They work like
associative arrays or hashes found in Perl and consist of key-value
pairs.
A dictionary key can be almost any Python type, but are usually
numbers or strings. Values, on the other hand, can be any arbitrary
Python object.
Dictionaries are enclosed by curly braces ({ }) and values can be
assigned and accessed using square braces ([]).](https://image.slidesharecdn.com/1-introduction1-250401061226-93cedabc/85/1-Introduction-to-Python-features-of-python-history-of-python-1-pptx-38-320.jpg)
![Dictionary Example
# Python Dictionary - Example Program
dictionary1 = {}
dictionary1['one'] = "This is one"
dictionary1[2] = "This is two"
smalldictionary = {'name': 'Devraj','id':9388, 'branch': 'cs'}
print dictionary1[2] # this will print the values for 2 key
print dictionary1['one'] # this will print the value for 'one' key
print smalldictionary # this will print the complete dictionary
print smalldictionary.keys() # this will print all the keys
print smalldictionary.values() # this will print all the values](https://image.slidesharecdn.com/1-introduction1-250401061226-93cedabc/85/1-Introduction-to-Python-features-of-python-history-of-python-1-pptx-39-320.jpg)
