007 Python Introduction

for more updates visit: www.python4csip.
com
Name derived from famous BBC

comedy show namely Monty
Python’s flying circus
VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &

SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
for more updates visit: www.python4csip.com
Python was created by Guido Van Rossum

The language was released in February I991
Python got its name from a BBC comedy series from seventies-
“Monty Python‟s Flying Circus”
Python can be used to follow both Procedural approach and
Object Oriented approach of programming
It is free to use
Python is based on or influenced with two programming
languages:
ABC language [replacement of BASIC]
Modula-3
Easy to use Object oriented language

Expressive language
Interpreted Language
Its completeness
Cross-platform Language
Fee and Open source
Variety of Usage / Applications

• Python is compact and very easy to use object oriented

language with very simple syntax rules. It is very high level
language and thus very-very programmer -friendly
• More capable to express code‟s purpose than many othr

language like – swapping of two numbers:
In C++ In Python
int a=2, b=3, tmp; a,b=2,3
tmp=a; a,b=b,a
a=b;
b=tmp;
• It is interpreted not compiled, thus executes code line by line

and it makes python easy-to-debug and suitable for beginners
and advanced users
• When you install Python, you get everything i.e. you don‟t need
to install additional libraries. All functionality is available with
Python additional library. Features like web-pages, database
connectivity, GUI features are available in Python standard
library. Python follows – “Battery included” philosophy

• Python can run equally well on variety of platforms – Windows,

Linux/UNIX, Macintosh, supercomputers, smart phones. Python is
portable language.
• It is feely available i.e. without any cost can be downloaded

from www.python.org.
• It is also open source i.e. you can modify, improve/extend an
open-source software

• Python is being used in many diverse

fields/applications, some of which are:
• Scripting
• Web Applications
• Game Development
• System Administrations
• Rapid Prototyping
• GUI Programs
• Database Applications

Not the fastest language

Lesser Libraries than C, Java, Perl
Not Strong on Type-binding
Not Easily convertible

• Because of its interpreted nature Python is not fast as compare

to compiled language. Python is first compiled into an internal
byte-code which is then executed by Python interpreter.
• Python offers library support for almost all computing

programs, but its library is still not competent with languages
like C, java as they have larger collection available.

• Python is not very strong on data type checking i.e. “Type-

mismatch” issues. For example if you declare variable as
integer but later store a string value in it, Python will not raise
any error.
• Because of its lack of syntax, Python is easy to program but it

becomes disadvantage when it comes to translate python
program to another language.

Before we start working on Python we need to install Python in our

computer. There are multiple distributions available today:
Default Installation available from www.python.org is called

Cpython installation and comes with python interpreter, Python
IDLE(Python GUI) and Pip(package installer)
ANACONDA Python distribution is one such highly
recommended distribution that comes with preloaded many
packages and libraries(NumPy, SciPy, Panda etc)
Other Popular IDEs like Sypder, PytCharm, etc. Spyder IDE is
available as a part of ANACONDA.

After Python installation we can start working with python. In

Python we can work in 2 ways:
Interactive Mode
(Immediate
Python working Mode)
Ways
Script Mode

The default installation of CPython comes with Python

Interpreter, Python IDLE and pip(package installer). To work in
either interactive mode or script we need to open Python
IDLE
To work in interactive mode, follow the process given below:
(i) Click start button  All Programs  Python 3.6.x IDLE
Or
Click start button  All Programs  Python 3.6.x Python
(command line)

Interactive modes – one command at a time

Python executes the given command and gives the output.
In interactive mode we type command at IDLE prompt ( >>> )
For e.g if you type 20 + 30 in from of IDLE prompt
>>> 20 + 30 (command give by user)
50 (output given by python)
From the above example you can see than at >>> we have to
just give the command to execute and python we execute it if it
is error free otherwise gives an error.

( )
( )
( )
( )
( )
print (“Hello”)

Script Mode – multiple commands can be saved in a file as a

program and then we can execute the entire program
we type Python program in a file and then use the interpreter
to execute the content from the file.
Working in interactive mode is convenient for beginners and for
testing small pieces of code, as we can test them immediately.
But for coding more than few lines, we should always save our
code so that we may modify and reuse the code

In Python IDLE :

Click File  New
In new window type the commands you want to save in program
For example:
print(“Hello World!”)
FileSave to save file. Give extension .py to execute it as

python script

Save the
program
and press
F5
( )


Type the below code in script file:
#My First Program

print(“Hello World!”)
When you execute the script file output will be only

Hello World
Note: the first line starts from # which makes line as a
comment i.e. only for programmer information not for
interpreter. Comments are ignored by interpreter
To print or display output Python 3.x provides print() function.

Examples:-
print(“Welcome to Python”)
it will print Welcome to Python
print(„Python rocks!‟)
it will print Python rocks!
Note: Python allows both single quotation and double quotation
to enclose string. In any case both opening and closing must be
same.
print(„Look carefully”)
it will give error because both opening and closing
quotes are different.VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &
Note:
1) In Python 2.x print is a statement, not a function
2) Python is case-sensitive i.e. it will treat small letter and
capital letter as two different entities like m & M will be
treated differently in Python.
3) We can use up arrow (↑) and down arrow (↓) to select
previous command and press enter to recall and execute.
4) print statement is required only while working with
script mode otherwise in interactive mode values can be
printed without print statement
#This is my first program

#sample of basic statements
#print(“Watch out”)
print(“Johny Johny Yes Papa”)
print(“No Papa”)
(a) (b)
This is my first program sample of basic Watch out
statements Watch out Johny Johny Yes Papa
Johny Johny Yes Papa No Papa
No Papa
(c) (d)
Johny Johny Yes Papa This is my first program
No Papa Johny Johny Yes Papa
No PapaLittle Star
(a) “Sayonara” (b) „Sayonara‟

(c) “Sayonara‟ (d) „Sayonara”
(e) {Sayonara}

• Who developed Python Programming Language?

• Is Python Object Oriented Language?
• Python is a high level interpreted language. What does it means
• What does cross-platform means?
• Python is free and open source. What do you understand by
this feature?
• What is the difference in interactive mode and Script mode in
Python?


007 Python Introduction

Uploaded by

Copyright:

Available Formats

007 Python Introduction

Uploaded by

Document Information

Original Description:

Copyright

Available Formats

Share this document

Share or Embed Document

Sharing Options

Did you find this document useful?

Is this content inappropriate?

Copyright:

Available Formats

007 Python Introduction

Uploaded by

Copyright:

Available Formats

for more updates visit: www.python4csip.

Name derived from famous BBC

VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &

Python was created by Guido Van Rossum

Easy to use Object oriented language

VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &

• Python is compact and very easy to use object oriented

• More capable to express code‟s purpose than many othr

• It is interpreted not compiled, thus executes code line by line

VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &

• Python can run equally well on variety of platforms – Windows,

• It is feely available i.e. without any cost can be downloaded

VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &

• Python is being used in many diverse

VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &

Not the fastest language

VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &

• Because of its interpreted nature Python is not fast as compare

• Python offers library support for almost all computing

VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &

• Python is not very strong on data type checking i.e. “Type-

• Because of its lack of syntax, Python is easy to program but it

VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &

Before we start working on Python we need to install Python in our

Default Installation available from www.python.org is called

VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &

After Python installation we can start working with python. In

VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &

The default installation of CPython comes with Python

VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &

Interactive modes – one command at a time

VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &

VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &

Script Mode – multiple commands can be saved in a file as a

VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &

In Python IDLE :

FileSave to save file. Give extension .py to execute it as

VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &

VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &

VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &

Type the below code in script file:

#My First Program

When you execute the script file output will be only

To print or display output Python 3.x provides print() function.

#This is my first program

(a) “Sayonara” (b) „Sayonara‟

VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &

• Who developed Python Programming Language?

VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &

You might also like