Python 1st mid sem exam of 3rd semester

 

Python 1st mid sem exam of 3rd semester Under Ranchi University

 

Topics covered in this blog

• Keywords and Identifiers
• Data types and its function
• List and its function
• Dictionary and its function
• Conditional construct
• Indentation and Commands
• Practical Question
  

 

 

Keywords and Identifiers

Python has a set of keywords that are reserved words that cannot be used as variable names, function names or any other identifiers.




Keywords and Description


and = A logical operator.

as = The as keyword is used to create an alias. when importing the module. For example -
 

 

import calendar as c
print(c.month_name[1])

 

 

We can refer to the calendar module and now we can refer to the calendar module by using a instead of calendar.


assert = The assert keyword is used when debugging the code.

The assert keyword lets you test if a condition in your code returns. True, if not, the programmer will raised an assertion error.

 

For example - 

x = "Hello"

#if condition returns True, then nothing happens

asser x == "Hello"

#if condition returns false, assertion error is raised.

assert x == "goodbye"

 

break = To break out of a loop. For example
 

 

for i in range(9):
    if i > 3:
       break
       print(i)

 

class = To define a class. For example
 

 

class Person:
      name = "Atul"
      age = 22

 

 

Continue = This keyword is used to end the current iteration in a for loop (or a while loop) and continues to the next iteration.

For Example
 

 

for i in range(9):
    if i == 3: 
       continue
       print(i)

 

def = def is used to define a function. For example
 

 

def myfunction():
    print("Hello world!")
   

myfunction

 

del = To delete a class. For example
 

 

class myclass:
      name = "Atul"
     

del myclass
print(myclass)

 

output   

NameError: name 'myclass' is not defined
 

if = This keyword is used to create a conditional statement (if statement) and allows you to execute a block of code only if a condition is True.

 

x = 5
if x > 3:
   print("Yes")

 

 

elif = This keyword is used in conditional statement and is short for else if. For example
 

 

for i in range(-5, 5):
    if i > 0:
        print("Yes")
    elif i == 0:
        print("WHATEVER")
    else:
        print("No")
        

 

else = This is used in also conditional statement. For example 

 

x = 2
if x > 3:
   print("Yes")
else:
   print("No")

 

 

except = Used with expectations, what to do when an exception occurs. For example
 

 

try:
   x > 3
except:
   print("Something went wrong")
   print("Even if it is raised an error, the program keeps running")
  

 

 

NOTE = (x>3) will raise an error because x is not defined.


output - Something went wrong...even if it raised an error, the program keeps running.    

 

 

global = Declare a global variable inside a function and use it outside the function. For example
 

def myfunction():
    global x
    x = "hello Atul"
    
    
myfunction()

print(x)

 

import = import the datetime module and display the current date and time. For example
 

 

import datetime

x = datetime.datetime.now()
print(x)

 

 
in = The in keywork is used to check if a value is present in a sequence (list, range and string etc)

The "in" keyword is also used to iterate thorugh a sequence in a for loop.

 

fruits = ["apple", "banana", "cheery"]

if "banana" in fruits:
    print("Yes")
    

 

 

lambda keyword = The lambda keyword is used to create small anonymous functions.

lambda function can take any number of argument, but can only have one expression.
 

 

x = lambda a : a + 10
print(x)

 

 

 

Python Identifiers

 

Python identifiers is the name we give to identify a variable, function class module or other object. This means whenever we want to give an entity a name, thats called identifier.



so, myvariable
    variable_1
    variable_for_print

• An identification start with the digit, so while variable1 is valid, 1variable is not valid.

• We cant use special symbol !, #, @, %, $, etc in our identifiers.

 

For Example

x = int(input("Enter first number"))
y = int(input("Enter second number"))
sum = x + y
print("The sum of x and y is " , sum)

 

Q) wap to validate the credentials using python with userid and password

 

 

def login():
     userid = input("Enter userid")
     pwd = input("Enter password")
     
     if(userid == "Atul" and pwd == "akku"):
        print("You are a valid user")
     else:
        print("You are not a valid user")
     

login()

 

 

Q) wap to display a largest number in python using(if, elif, else)

 

def largest():
    x = int(input("Enter the value of x \n"))
    y= int(input("Enter the value of y \n")) 
    z = int(input("Enter the value of z \n"))
    
    if(x >= y and y >= z):
      print("x is greater than y")
    elif(y > x and y > z):
      print("y is greater than z")
    else:
      print("z is greater than of all among of them")

largest()        

 

 

List and its function

List is a data type function which store any types of data such as integer, number, string etc.

There is a so many functions in this list -

• append()
• insert()
• clear()
• count()
• copy()
• copy()
• remove()
• index()
• reverse()
• extend()

 

append() = It is a function is used to insert an element and ethe end of the list.

i = [5, 10, 15, 8, 21]
i.append(30)
print(i)

 

output

[5, 10, 15, 8, 21, 30]

 

Insert = It is used to insert an element in a specific position in the insert(). Its contains two argument so first contains index number and second the elements.

 

 

i = [5, 10, 15, 8, 21]
i.insert(2, 6)
print(i)

 

output

[5, 10, 6, 15, 8, 21]
 

 

clear() = clear function is used to remove all the elements from the list.
 

 

i = [5, 10, 15, 8, 21]
i.clear()
print(i)

 

output


[]
 

 

count() = It is used to count the number of times an element appear in the list. In this function we have to pass the elements name.

 

i = [5, 10, 15, 8, 10 21]
i.count(10)
print(i)

 

output

2
 

 

copy = copy is used to copy one list into another list.

 

i = [5, 10, 15, 8, 10 21]
j.copy()
print(j)

 

output

[5, 10, 15, 8, 10 21]


 

pop() = pop() function is used to remove an elements from specific position by passing its index number.


 

 

i = [5, 10, 15, 8, 21]
i.pop(2)
print(i)

 

output


[5, 10, 8,21]


 

remove() = remove function is used to remove an elements by passing the elements name in function.

 

i = [5, 10, 15, 8, 21]
i.remove(10)
print(i)

 

 
output


[5, 15, 8, 21]




index() = index() function is used to display the index number or position on the elements in the list. In this function we have to pass the elements name.

 

i = [5, 10, 15, 8, 21]
i.index(15)
print(i)

 

 

output


2

 

reverse() = reverse() function is used to reverse all of the elements in a list.


 

 

i = [5, 10, 15, 8, 21]
i.reverse()
print(i)

 

output

[21, 8, 15, 10, 5]

 

 

extend() = extend() is used to insert all the elements in the last position in the list.
 

 

i = [5, 10, 15, 8, 21]
name = ["atul", "hackingtruth"]
i.extend(name)
print(i)

 

sort() = sort function is used to sort the elements in ascending order or descending order. By default, sort function store the
elements in ascending order. If we want to display the elements in descending order then we have to use (reverse=true)
 

 

i = [5, 10, 15, 8, 21]
i.sort()
print(i)

 

 

output

[5, 8, 10, 15, 21]
 

 

 

In Descending order

 

i = [5, 10, 15, 8, 21]
i.sort(reverse=true)
print(i)

 

output

[21, 15, 10, 8, 5]
 

 

 

Dictionary and its function

• Dictionary are used to store data values in key: value pairs.
• Dictionary are written with curly brackets and have keys and values.
• Dictionary items are ordered.
• Dictionary are changeable meaning that we can change add or remove items after the dictionary has been created.
• Duplicates values are not allowed.
• Dictionary cannot have two items with the same keys.

• clear()
• copy()
• get(keyname)
• fromkeys()
• keys()
• values()
• items()
• pop()
• popitems()
• update()

 

 
clear() = clear methods are used to remove all the elements from the dictionary list.

 

cybersecurity = {
               "brand" : "Hacking Truth",
               "domain" : "hackingtruth.org",
               "service" : "penetration testing"
               }
               

cybersecurity.clear()

 

output

{}               
 

 

copy() = copy function is used to copy one dictionary into another dictionary object.
 

 

a = {"science" : 67, "maths" : 89}
b = a.copy()
print(a)
print(b)

 

output

{"science" : 67, "maths" : 89}
{"science" : 67, "maths" : 89}
 

 

get() = The get method returns the value of the item with the based on key.
 

 

car = {
        "brand" : "BMW",
        "model" : "Mustand",
        "year" : "1964"
      }
      
      
x = car.get("model")
print(x)

 

 

output

mustang
 
 

 

fromkey() = It is used to create a dictionary based on the key variable and values variable.
 

key = [1, 2, 3]
value = {"java", "c++", "android"}
dict = fromkeys(key, value)
print(dict)

 

 
output

1 : "java", 2 : "c++", 3 : "android"

 

keys() = It is used to returns all the keys from the dictionary.
 

 

dict = {a : "atul", b : "kumar"}
print(dict.keys())

 

output


dict_keys(['a', 'b'])
 

 

values() = values is used to return all the value from the dictionary.
 

 

dict = {1: "java", 2: "c++", 3: "android"}
value = dict.values()
print(value)

 

output

(["java", "c++", "android"])
 

 

 
item() = item() is used to return all the keys and value

 

  
dict = {1: "java", 2: "android"}
item = dict.items()
print(item)


  

 

pop() = pop() is used to remove an element based on the key path.
 

 

hisdict = {
          "brand" : "ford",
          "model" : "mustand",
          "year" : "1964"
          }
          
hisdict.popitem()
print(hisdict)

 

 

output

{"brand" : "ford", "model" : "mustand"}
 

 

 

Conditional construct

In conditional construct python is a block of executed condition become true if condition is becoming not true if check all the elif blocks

If any of one elif block become true it will print the statement of respective elif block.

If none of the elif block becming true it executes the else block to define the condition construct. We have to write if inside the paramter and terminate will colon (:) symbol.


if(avg >= 75):
 

The body of the construct starts with indentation or block space is space of curly braces.

 

 

sub1 = int("Enter the marks of student1")
sub2 = int("Enter the marks of student2")
sub3 = int("Enter the marks of student3")



avg = (sub1 + sub2 + sub3)/3

if(avg >= 75):
   print("Grade A")
elif(avg >= 60 and avg < 75):
   print("Grade B")
elif(avg >= 50 and avg < 60):
   print("Grade C")
else:
   print("Grade D")
  

 

For loop = for i in marks:

i = variable (iterate, traverse)
marks = sequence(list, tuple)
 

 

In python for loop is used to iterate or traverse in the element of sequence. The sequence can be list tuple, list, dictionary or any string data type. We can stop the execution of for loop by using the break statement.

We can also give else block in for statement and the else block will block when all the condition becomes false even break statement also.
 

 

  
For example1

num = [5, 10, 15 ,20]
for i in num:
    print(i)



For example2

num = [5, 10, 15, 20]
sum = 0
for i in num:
     sum = sum + i
     
print("sum is " , sum)


marks = {"Atul" : 85, "hackingtruth" : 99}

name = input("Enter a name")

for student in marks:
     if(student == name):
        print(marks[student])
        break
     else:
        print("No such name exit")   




  
  

 

 

Practical Question

 

1Q) wap to add, mul, sub, divide using function ?

 

 

#!/usr/bin/python

a = int(input("Enter first value : "))
b = int(input("Enter second value : "))

def add():
    c = a + b
#    a = 5 + 5
    print("The sum of a and b is : " , c)

def sub():
    c = a - b
#    b = 5 - 5
    print("The subtraction of a and b is : " , c)

def mul():
    c = a * b 
#    c = 5 * 5
    print("The multiplication of a and b is : " , c)

def div():
    c = a / b
#    d =  5 / 5
    print("The division of a and b is : " , c)


add()
sub()
mul()
div() 

 

2Q) wap to validate a user using dictionary?

 

 

#!/usr/bin/python

Dict = {"atul" : "atul143", "hackerboy" : "hackerboy143" }

a = input("Enter the username : ")
b = input("Enter the password : ")

if a and b not in Dict:
   print("You are a valid user")
else:
   print("You are not a valid user") 

 

 

 

3Q) wap to using Tk() function interface to add the number?

 

 

 

from tkinter import *

win = Tk()
win.geometry("400x400")

Label(win, text="Your First Number:").grid(row=0, column=0)
Label(win, text="Your Second Number:").grid(row=1, column=0)

# define the label, step 1
label3 = Label(win)

# set grid, step 2
label3.grid(row=3, column=1)

first_no = IntVar()
second_no = IntVar()



# same goes for here
e1 = Entry(win, textvariable=first_no).grid(row=0, column=1)
e2 = Entry(win, textvariable=second_no).grid(row=1, column=1)


def add():
    sum = first_no.get() + second_no.get()
    label3.config(text="your final number is:" + str(sum))

mybutton = Button(win, text=("Calculate!"), command=add).grid(row=2, column=1)

win.mainloop()

 

 

 

 

 

 5Q) wap in python using append, remove, reverse and extend list item?

 

 

#!/usr/bin/python

listitem = [5, 10, 15, 8, 21]
print("Before performing the operation " , listitem)

#append

listitem.append(30)
print("After appending some values : " , listitem)

#remove

listitem.remove(15)
print("Now, Removing 15 no element from list : " , listitem)
#
#reverse

listitem.reverse()
print("After reversing values : " , listitem)

#extend

name = ["atul", "hackingtruth"]
listitem.extend(name)
print("after using extending func : " , listitem)

 

 

 

 

 

 

6Q) wap to insert product ID, product name and product price in list date types and display it?

 

#!/usr/bin/python

pid = int(input("Enter the product id (1, 2, 3...) : "))
pname = input("Enter the  product name : ")
pprice = input("Enter the product price : ")

list1 = []

list1.append(pid)
list1.append(pname)
list1.append(pprice)
print(list1)

 

 

 

 

 

 

7Q) wap to create a dictionary and add all of the value and also display maximum and minimum value?

 

 

#!/usr/bin/python

Dict = {"x" : 50, "y" : 60, "z" : 45}
print(Dict)
total = 0
for i in Dict.values():
    total = total + i

print("Sum " , total)
print("The maximum value is " , max(Dict.values()))
print("The Minimum value is " , min(Dict.values()))

 

 

 

 

 

 

8Q) create a dictionary and add some item in dictionary and display it?

 

 

#!/usr/bin/python3

a = input("Enter the key attribute name : ")
b = input("Enter the value of key attribute : ")

Dict = {}
Dict.update({a : b})
print(Dict)

 

 

 

 

Disclaimer

 

All tutorials are for informational and educational purposes only and have been made using our own routers, servers, websites and other vulnerable free resources. we do not contain any illegal activity. We believe that ethical hacking, information security and cyber security should be familiar subjects to anyone using digital information and computers. Hacking Truth is against misuse of the information and we strongly suggest against it. Please regard the word hacking as ethical hacking or penetration testing every time this word is used. We do not promote, encourage, support or excite any illegal activity or hacking.