UGC NET Paper 1 Mathematical Reasoning & Aptitude.pdf
Python basics
1.
2. Introduction-
What is Python?
Python History
Features of Python
Applications of Python
Architecture and Working of Python
Python Constructs
Python vs Java vs C++
3. Python is a General Purpose object-oriented
programming language, which means that it
can model real-world entities. It is also
dynamically-typed because it carries out
type-checking at runtime.
Python is an interpreted language.
4. Guido van Rossum named it after the comedy
group Monty Python
5. Python was developed in the late 1980s and was
named after the BBC TV show Monty Python’s
Flying Circus.
Guido van Rossum started implementing Python
at CWI in the Netherlands in December of 1989.
This was a successor to the ABC programming
language which was capable of exception
handling and interfacing with the Amoeba
operating system.
On October 16 of 2000, Python 2.0 released with
many new features.
Then Python 3.0 released on December 3, 2008
6. Python is the “most powerful language you
can still read”, Says Paul Dubois
Python is one of the richest Programming
languages.
Going by the TIOBE Index, it is the Second
Most Popular Programming Language in the
world.
7. Easy
When writing code in Python, you need fewer
lines of code compared to languages like
Java.
Interpreted
It is interpreted(executed) line by line. This
makes it easy to test and debug.
Object-Oriented
The Python programming language supports
classes and objects and hence it is object-
oriented.
8. Free and Open Source
The language and its source code are available to the
public for free; there is no need to buy a costly license.
Portable
Since Python is open-source, you can run it on Windows,
Mac, Linux or any other platform. Your programs will work
without any need to change it for every machine.
GUI Programming
You can use it to develop a GUI (Graphical User Interface).
One way to do this is through Tkinter.
Large Python Library
Python provides you with a large standard library.
You can use it to implement a variety of functions without
the need to reinvent the wheel every time. Just pick the
code you need and continue
9. Build a website using Python
Develop a game in Python
Perform Computer Vision (Facilities like face-
detection and color-detection)
Implement Machine Learning (Give a computer
the ability to learn)
Enable Robotics with Python
Perform Web Scraping (Harvest data from
websites)
Perform Data Analysis using Python
Automate a web browser
Perform Scripting in Python
Build Artificial Intelligence
10. Parser
It uses the source code to generate an
abstract syntax tree.
Compiler
It turns the abstract syntax tree into Python
bytecode.
Interpreter
It executes the code line by line in a REPL
(Read-Evaluate-Print-Loop) fashion.
11. Functions in Python
Classes in Python
Module Packages in Python
Packages in Python
List in Python
Tuple in Python
Dictionary in Python
Comments and Docstrings in Python(#, ’’ ’’ “)
12. How does Python get its name?
What are the Features of Python that make it
so popular?
Define Modules in Python?
What is the difference between List and Tuple
in Python?
Compare Python with Java
13. A variable is a container for a value. It can be
assigned a name, you can use it to refer to it
later in the program.
Based on the value assigned, the interpreter
decides its data type.
x=45 type =integer
Name=“seed” type = string
List1=[1,22,33] type = list
14. A variable can have a short name (like x and
y) or a more descriptive name (age, carname,
total_volume).
Rules for Python variables:
1. A variable name must start with a letter or the
underscore character
2. A variable name cannot start with a number
3. A variable name can only contain alpha-numeric
characters and underscores (A-z, 0-9, and _ )
4. Variable names are case-sensitive (age, Age and
AGE are three different variables)
16. assign a value to Python variables, you don’t
need to declare its type
type the value after the equal sign(=).
You cannot use Python variables before
assigning it a value.
You can’t put the identifier on the right-hand
side of the equal sign, though. The following
code causes an error.
You can’t assign Python variables to a
keyword.
17. You can assign values to multiple Python variables in one
statement.
1. pin, city=11,‘Pune'
print(pin , city)
2. a,b,c = 11,22,33
print(a)
print(b)
print(c)
you can assign the same value to multiple Python
variables.
a=b=7
print(a,b)
18. You can also delete Python variables using
the keyword ‘del’.
a='red'
del a
19. Python has five standard data types −
Numbers
String
List
Tuple
Dictionary
20. Number data types store numeric values.
Number objects are created when you assign
a value to them.
For example −
var1 = 1 var2 = 70
Python supports four different numerical
types −
1. int (signed integers)
2. float (floating point real values)
3. complex (complex numbers)
21. x = 11 # int
y = 2.85 # float
z = 4+1j # complex
Float can also be scientific numbers with an
"e" to indicate the power of 10.
x = 35e3 # float
y = 12E4 # float
z = -87.7e100 #float
22. You can convert from one type to another with the int(), float(),
and complex() methods:
x = 1 # int
y = 2.8 # float
z = 1j # complex
#convert from int to float:
a = float(x)
#convert from float to int:
b = int(y)
#convert from int to complex:
c = complex(x)
Note: You cannot convert complex numbers into another
number type.
x = str("s1") # x will be 's1‘
y = str(2) # y will be '2‘
z = str(3.0) # z will be '3.0'
23. isinstance() function to tell if Python
variables belong to a particular class. It takes
two parameters- the variable/value, and the
class.
>>> print(isinstance(a,complex))
24. 2. Strings
A string is a sequence of characters. Python
does not have a char data type, unlike C++
or Java. You can delimit a string using single
quotes or double-quotes.
>>> city='Ahmednagar'
>>> city
25. What do you mean by scope?
What are the types of variable scope?
What is scope of variable with example?
What are python variables?
How do you declare a variable in Python 3?
26. Operator Name Example
+ Addition a+b
- Subtraction a-y
* Multiplication a*y
/ Division a / b
% Modulus a % b
** Exponentiation a ** b
// Floor division a //b
27. Operator Example Same As
= x = 5 x = 5
+= x += 3 x = x + 3
-= x -= 3 x = x - 3
*= x *= 3 x = x * 3
/= x /= 3 x = x / 3
%= x %= 3 x = x % 3
//= x //= 3 x = x // 3
**= x **= 3 x = x ** 3
|= x |= 3 x = x | 3
28. Operator Name Example
== Equal x == y
!= Not equal x != y
> Greater than x > y
< Less than x < y
>= Greater than or equal
to
x >= y
<= Less than or equal to x <= y
29. Operator Description Example
and Returns True if both
statements are true
x < 5 and x < 10
or Returns True if one of
the statements is true
x < 5 or x < 4
not Reverse the result,
returns False if the
result is true
not(x < 5 and x < 10)
30. Identity operators are used to compare the
objects, not if they are equal, but if they are
actually the same object, with the same
memory location:
Operator Description Example
is Returns True if both
variables are the same
object
x is y
is not Returns True if both
variables are not the
same object
x is not y
31. Membership operators are used to test if a
sequence is presented in an object
Operator Description Example
in Returns True if a sequence
with the specified value is
present in the object
x in y
not in Returns True if a sequence
with the specified value is
not present in the object
x not in y
32. Bitwise operators are used to compare
(binary) numbers:
Operator Name Description
& Binary AND Sets each bit to 1 if both bits are 1
| Binary OR Sets each bit to 1 if one of two bits is 1
^ Binary XOR Sets each bit to 1 if only one of two bits is
1
~ Binary NOT Inverts all the bits
<< Zero fill left shift Shift left by pushing zeros in from the
right and let the leftmost bits fall off
34. Strings in Python are identified as a contiguous
set of characters represented in the quotation
marks.
strings in Python are arrays of bytes representing
unicode characters.
Python allows for either pairs of single or double
quotes
print("Hello")
print(‘Hello’)
Assign String to a Variable
a = "Hello"
print(a)
35. You can assign a multiline string to a variable
by using three single or double quotes:
Example
◦ Name = “ ” ” Hello,I am an Interpreter “ “ “
◦ print(Name)
◦ Name = ‘ ‘ ‘ Hello,I am an Interpreter ’ ’ ’
◦ print(Name)
36. str = 'Hello World!'
print (str) # Prints complete string
print str * 2 # Prints string two times
print str + "TEST" # Prints concatenated string
37. You can return a range of characters by using the slice
Specify the start index and the end index, separated by a
colon, to return a part of the string.
To display only a part of a string ,use the slicing operator
[].
print(str[0]) # Prints first character of the string at 0th
index or position
print str[2:5] # Prints characters starting from 2nd to 4th
character
print str[2:] # Prints string starting from 2nd character
Note: The first character has index 0.
38. print(b[:5]) # print the characters from the
start to position 5 (not included)
print(b[2:]) # print the characters from
position 2, and to the end
Use negative indexes to start the slice from the end of the
string
print(b[-5:-2]) #
H E L L O 7
[0] [1] [2] [3] [4] [5] Positive
index
[-6] [-5] [-4] [-3] [-2] [-1] Negative
index
39. Python Strings can join using the
concatenation operator +.
a='Do you see this, '
b='$$?'
a+b
a='10'
print(2*a)
