3. Why to Learn Python?
Python is a MUST for students and working professionals to become a great Software Engineer specially when they are
working in Web Development Domain. I will list down some of the key advantages of learning Python:
Python is Interpreted − Python is processed at runtime by the interpreter. You do not need to compile your program
before executing it. This is similar to PERL and PHP.
Python is Interactive − You can actually sit at a Python prompt and interact with the interpreter directly to write your
programs.
Python is Object-Oriented − Python supports Object-Oriented style or technique of programming that encapsulates
code within objects.
Python is a Beginner's Language − Python is a great language for the beginner-level programmers and supports the
development of a wide range of applications from simple text processing to WWW browsers to games.
5. Area where python is used
Web development
Software development
Machine Learning,
IOT
Data analysis
App Development
Game Development
6. History
Python is developed by Guido van Rossum in 1989 at the National Research Institute for Mathematics and
Computer Science in the Netherlands it was the successor to ABC and capable of exception handling and
interfacing with the Amoeba operating system
Python is derived from:
Modula-3,
C,
C++
Unix shell
Other scripting languages.
Python is available under the GNU General Public License (GPL).
The GNU General Public License is a free, copyleft license for software and other kinds of works.
7. Features
1. Easy-to-learn and understand
2.. A broad standard library
3.Open Source
4. Interactive Mode
5. Portable (Platform in dependent)
6. Extendable
7. Databases
8. GUI Programming
9. Object Oriented Programming.
10. It can be used as a scripting language
8. Features
9. Object Oriented Programming.
10. It can be used as a scripting language
11. It provides very high-level dynamic data types and supports dynamic type checking.
12.It supports automatic garbage collector.
13. Less line of code
Python uses two strategies for memory Management:
Reference counting:
Garbage collection:
9. Python is available
Unix, Linux
Win 9x/NT/2000
Macintosh (Intel, PPC, 68K)
OS/2
DOS (multiple versions)
Palm OS
Nokia mobile phones(Symbian)
10. Python Installation
1. Go to www.python.org
2. Go to Download menu
3. Click on windows menu
4. Download Python (what ever version you want.
5. Double click on downloaded Python.exe file and install it
11. Set environment variable
Right click on My computer
Click on Properties
Then click on advance system setting In left hand side of the windows screen.
Then click on Set Environment variables
Now click on first New button and Add following
12. Set environment variable
1. Select “path” variable in system variables
2. Click on edit button
3. Add following path in the path variable
C:Users[Your_Current_User_Name]AppDataLocalProgramsPythonPython36;
4. Then click on ok Button.
5. Now open command prompt and type python
If python shall is running then environment variable is set properly.
13. Python Basic syntax
Python Identifiers
Reserved Words
Comments in Python
Input output In Python
Variable Types
Delete variable in python
14. 1. Python Identifiers
A Python identifier is a name used to identify a variable, function, class, module or other object. An identifier starts with:
Python does not allow A letter A to Z or a to z
An underscore (_) followed by zero more letters,
Underscores and digits (0 to 9).
@, $, and % within identifiers.
Python is a case sensitive programming language.
White specs not in b/w the catheters
E.g. My Name=“mukul”
15. Reserved Words
and from while
assert finally yield
break for with
class from try
continue global return
def If Raise
elif Import print
else In pass
is Except or
del lambda not
16. 2. Multi-Line Statements
Statements in Python end with a new line. Even though, allow the use of the line continuation character () to denote that the
line should continue. For example −
• total = item_one +
• item_two +
• item_three
17. 3. Comments in Python
A hash sign (#) is used to define a comment in python .Python compile ignore the line, which are started from #
1. Single line comment
Eg. # Python is a awesome language.
2. Multiline comment
Eg. “”” Python is a awesome
language isn’t it”””
18. 4. Input output In Python
Input:
User can give the input to python program by input keyword
Ex. i=input() #in python 3.6
Ex. i=raw_input () # in python 2.7
Output:
Print keyword is used for print something on monitor
Ex. print(“Python is a awesome language”)# in python
version 3.6
Print “Python is a awesome language” # in python
version 2.7
19. 5. Variable Declaration
Variables reserved the memory locations to store values.
Assignee value to variable
counter = 500 # An integer assignment
miles = 6000.0 # A floating point
name = “Mukul Kirti Verma” # A string
Note:-
1.In python no need to define main().
2.In python no need to define data type for variables.
20. 6. Multiple Assignment
single value to several variables
a = b = c = 1
Multiple objects to multiple variables
a, b, c = 1,2,"john"
21. Delete variable in python
To delete the reference to a number object by using the del statement.
Syntax of the del statement is −
del var1,var2,var3,…..,varN
Ex x,y,z=6,7,8
del x,y,z
22. Python Data types
1. Int
2. Float
3. Complex
4. Boolean
5. String
6. List
7. Tuple
8. Dictionary
23. Types of Operator
Python supports the following types of operators:
1.Arithmetic Operators
2.Comparison (Relational) Operators
3.Assignment Operators
4.Logical Operators
5.Bitwise Operators
6.Membership Operators
7.Identity Operators
25. Comparison Operators
Operator Example
== compare two values that they are
equal or not
(a==d) return True if they are equal ,return
False if they are not equal
!= compare two values that they are
equal or not
(a==d) return False if they are equal ,return
True if they are not equal
<> Similar to != Similar to !=
> Compare that left side value is
greater then the right side value
a>b return true if a is greater then b
< Compare that right side value is
greater then left side value
a<b return true if b is greater then b
>= Compare that left side value is
greater then or equal to right side value
a>=b return true if a is greater then b or equal
to b
<= Compare that right side value is
greater then or equal to left side value
a<=b return true if a is Lesser then b or equal
to b
26. Assignment Operators
= Example
= c=a+b it will assigns a+b value
to c
+= c+=a it is equivalent to c=c+a
-= c-=a it is equivalent to c=c-a
*= c*=a it is equivalent to c=c*a
/= c/=a it is equivalent to c=c/a
%= c%=a it is equivalent to c=c%a
**= c**=a it is equivalent to c=c**a
//= c//=a it is equivalent to c=c//a
27. Bitwise Operators
Operator Example
& Binary AND 1 & 0 = 0
| Binary OR 1 | 0 = 0
^ Binary XOR 1 ^ 0 = 1
~ Binary Ones
complement
~001=1010
>> Binary Right Shift a=2;
2>>1 =1;
<< Binary Left shift a=2;
a<<1=4;
29. Membership Operators
Operator Example
In Return true if it finds a variable in
the specified sequence and false if
not finds
2 in (2,3,5,6) return
true
not in Return true if it finds a variable in
the specified sequence and false if
not finds
2 not in (2,3,5,6)
return false
30. Identity Operators
Operator Example
Is Return true if the variables on
either
side of the operator point to the
same object and false otherwise
x is y return True if id(x) == d(y)
Is not Return false if the variables on the
either side of the operator point
to
the same object and true
otherwise
X is not y return true if id(x)!=id(y)
31. Operators Precedence
S. No. Operator Description (1. Has max prescience and7. has
lowest prescience )
1 peranthsis
//(floor division)
** Exponentiation
%(Modulo),
2 ~ (complement)
3 (Multiply), /(Division
4 + (Addition) ,-- (subtraction)
5 >>,<< (Right and left bitwise shift)
6 & (Bitwise ‘AND’)
7 ^ (Bitwise XOR), | (regular ‘OR’)
33. Python Type Conversion and Type Casting
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
34. Key Points to Remember:
In python type Conversion is the conversion of object from one data type to another data type.
Implicit Type Conversion is automatically performed by the Python interpreter.
Python avoids the loss of data in Implicit Type Conversion.
Explicit Type Conversion is also called Type Casting, the data types of object are converted using predefined function
by user.
In Type Casting loss of data may occur as we enforce the object to specific data type.
39. Python - Loops
Loop allow us to execute the set of statement for multiple times.
In python three types of loops are define
1. for
2. while
3. nested loop
4. for else
5. while else
40. Continue….
It has the ability to iterate over the items of any sequence, such as a list or a string.
Syntax:
for i in sequence:
statements(s)
41. While Loop
A while loop statement in Python programming language repeatedly executes a target statement as long as a given
condition is true.
Syntax:
while expression:
statement(s)
43. Standard Data Types
Python has five standard data types −
• Numbers
• String
• List
• Tuple
• Dictionary
44. Numbers in python
Number data types store numeric values. They are immutable data
types, means that changing the value of a number data type results
in a newly allocated object.
var1 = 1
var2 = 10
Python supports Three different numerical types −
int (signed integers)
float (floating point real values)
complex (complex numbers)
45. Mathematical Function
Function Description
abs() Return absolute value of x
exp() exp(x)=(e)power(x)
Floor() floor(x) :it Return floor value of x
Log() log(x) : it return logarithmic value of x
Max() max(x1,x2,x3…,xn) : it return max element in a list
Min() min(x1,x2,……xn): it return min element in a list
Pow() pow(x,y) : it return x**y
Ceil() Return ceiling value
46. Mathematical constraints
Sr.
No.
Constants & Description Example
1 Pi The mathematical constant
pi.
i=numpy.pi
Output :
i=3.141592653589793
2 e The mathematical constant
e.
i=numpy.e
Output :
i=2.718281828459045
47. Strings
Definition:-String are nothing but set of character.
Ex.
• var1 = ‘Hello scimox'
• var2 = "Python Programming“
• var3=“””hello my name is
mukul kirti verma”””
49. String Methods
Method
count returns occurrences of substring in string
isupper returns if all characters are uppercase characters
join Returns a Concatenated String
index Returns Index of Substring
isalnum Checks Alphanumeric Character
isdecimal Checks Decimal Characters
Isdigit Checks Digit Characters
isprintable Checks Printable Character
51. String Methods
Method Description
rindex Returns Highest Index of Substring
splitlines Splits String at Line Boundaries
rsplit Splits String From Right
find Find element in string
isspace Checks Whitespace Characters
swapcase swap uppercase characters to lowercase; vice versa
islower Checks if all Alphabets in a String are Lowercase
isnumeric Check whether all element of string in are numeric
52. String Special Operators
Operator Description
+ For Concatenation
* Repetition
[] Slice
[ : ] Range Slice
in Membership
not in Membership
r/R Raw String
53. Python Lists
The list can be written as a collection of comma-separated values (items) between square brackets. Values can be any type of.
Operation
1. Insert
2. Update
3. Delete
Eg.
list1 = ['physics', 'chemistry', 1997, 2000];
list2 = [1, 2, 3, 4, 5 ];
list3 = ["a", "b", "c", "d"]
54. Some other Operation on list
Expression Result
list1+list12 It will concatenate list1 and list2
len(list1) It will return length of list1
(‘ok',) * 4 It will return list with 4 element
with value ‘ok’
x in (x,y,z) It will check membership of x in list
max(list1) It will return max element in list
min(list1) It will return min element in list
55. Tuple In Python
A tuple is a sequence of immutable Python objects. Tuples elements cannot be changed
Creating a tuple is as simple as putting different comma-separated values in and put in parenthese.
Ex.
Tuple1=(1,2,3,4,5)
Tuple1 = (‘abc', ‘xyz', 1, 3.0);
Tuple1 = "a", "b", "c", "d";
56. Tuples Operations
Expression Result
tup1+tup2 It will concatenate tup1 and tup2
len(tup1) It will return length of tup1
(‘ok',) * 4 It will return tuple with 4 element
with value ‘ok’
x in (x,y,z) It will check membership of x in
tuple
max(tup1) It will return max element in tuple
min(tup1) It will return min element in tuple
count Count element In tuple
index Return index of an element in tuple
57. Dictionary In Python
In python, dictionary is similar to hash or maps in c++. It consists key and value pairs. The value can be accessed by unique
key in the dictionary. Keys are unique within a dictionary while values may not be. The values of a dictionary can be of any
type, but the keys must be of an immutable data type such as strings, numbers, or tuples.values can be any data type.
1. Insert
2. Update
3. Delete
58. Built-in Functions & Methods
len(dict) Gives the total length of the dictionary.
str(dict) it would convert dictionary in string.
type() it would return the type of element of a key passed.
59. Function in python
A function is a block of code which is run only when, it is called.
Creating or defining a Function;
def functionname( parameters ):
[expression]
Ex.
def printme(str):
print(str)
printme(“hi”)
Output:
‘hi’
60. Calling a Function
you can execute function code by calling it from
another function or directly from the Python prompt.
def printme( str ):
print str
return;
printme(“hi")# Output: ‘hi’
printme(“hello") #Output: ‘hello’
61. Function Arguments
A function can be call by using the following
types of formal arguments −
1. Required arguments
2. Keyword arguments
3. Default arguments
4. Variable-length arguments
62. return Statement
The statement return statement quit a function, and optionally passing back an expression to its caller. A return statement with no arguments
returns none.
Ex.
def sum( arg1, arg2 ):
total = arg1 + arg2
print (sum( 5, 5 ));
print (sum)
Output:
10
10
63. Scope of Variables
There are two basic scopes of variables in python
1. Global variables
2. Local variables
Ex.
total = 0 This is global variable.
def sum( arg1, arg2 ):
total = arg1 + arg2
print( total )
return total
sum( 10, 20 )
print ( total )
64. Python GUI with Tkinter
Introduction to tkinter:
The tkinter package (“Tk interface”) is the standard Python interface to the Tk GUI toolkit. Both Tk and tkinter are available on
most Unix platforms, as well as on Windows systems. (Tk itself is not part of Python; it is maintained at ActiveState.)
Creating a GUI application using Tkinter is an easy task. All you need to do is perform the following steps −
Import the Tkinter module.
Create the GUI application main window.
Add one or more of the above-mentioned widgets to the GUI application.
Enter the main event loop to take action against each event triggered by the user.
66. Tkinter Label
This widget implements a display box where you can place text or images. The text displayed by this widget can be updated
at any time you want.It is also possible to underline part of the text (like to identify a keyboard shortcut) and span the text
across multiple lines.
Ex:
from Tkinter import *
root = Tk()
var = StringVar()
label = Label( root, textvariable=var, relief=RAISED )
var.set("Hey!? How are you doing?")
label.pack() root.mainloop()
67. Tkinter Entry
The Entry widget is used to accept single-line text strings from a user.
If you want to display multiple lines of text that can be edited, then you should use the Text widget.
If you want to display one or more lines of text that cannot be modified by the user, then you should use the Label widget.
Ex:
• from Tkinter import *
• top = Tk()
• L1 = Label(top, text="User Name")
• L1.pack( side = LEFT)
• E1 = Entry(top, bd =5)
• E1.pack(side = RIGHT)
• top.mainloop()
68. Tkinter Button
The Button widget is used to add buttons in a Python application. These buttons can display text or images that convey the
purpose of the buttons. You can attach a function or a method to a button which is called automatically when you click the
button.
Example:
• import Tkinter
• import tkMessageBox
• top = Tkinter.Tk()
• def helloCallBack():
• tkMessageBox.showinfo( "Hello Python", "Hello World")
• B = Tkinter.Button(top, text ="Hello", command = helloCallBack)
• B.pack() top.mainloop()