Review of Python - 10
Python: Introduction
Python is a high-level, interpreted, and easy-to-read programming language, used in: Web Development, AI & Data Science, Automation, Software Development, etc.Advantages of Python
1. Simple and Readable Syntax2. Extensive Libraries and Frameworks
3. Highly Portable
Disdvantages of Python
1. High Memory Consumption2. Weak in Mobile Computing
3. Runtime Errors
Python Syntax Basics
Printing Output>>> print("Hello World")
Comments
# Single line comment
‘’’ Multi line comment ‘’’
Variables
Variables are identifiers that store data.name = "Sujal"
age = 22
'name' and 'age' are variables that have value 'Sujal' and 22 respectively.
Rules
a. Cannot start with numbers
b. No spaces allowed
c. Case-sensitive
Data Types
| Data Types | Example |
|---|---|
| int | 10 |
| float | 3.14 |
| str | "Hello" |
| bool | True |
| list | [1,2,3] |
| dict | {"a":1} |
>>> print(type(age))
Input from User
>>> name = input("Enter name: ")>>> age = int(input("Enter age: "))
Operators
Operators are symbols or keywords that tell a computer to perform specific actions, computations, or logical manipulations on data. They are the building blocks used to connect values and variables (called operands) into actionable expressions.Arithmetic Operators
+ : Addition Operator
- : Subtraction Operator
* : Multiplication Operator
/ : Division Operator
// : Integer Division Operator
% : Modulus(Remainder) Operator
** : Exponent Operator
Comparison Operators
== : Check if equal
!= : Check if not equal
> : Check if greater
< : Check if lesser
>= : Check if greater than or equal to
<= : Check if lesser than or equal to
Logical Operators
and : Both True
or : Any True
not : Opposite
Program Flow Structures
Program flow controls how code executes.Review Practice ProgramsSequential Flow
Statments execute one after another in a sequence. >>> #Program to add two numbers >>> a=5 >>> b=3 >>> print(a+b)Selective/Conditional Flow
Such flow is to execute decision making and alternate outputs to a program.
Conditional Statements
if Statement >>> #Check if a person is adult. >>> age = 18 >>> if age >= 18: print("Adult") if-else Statement >>> #Check if a person is adult or minor. >>> if age >= 18: print("Adult") >>> else: print("Minor") if-elif Statement >>> marks = 75 >>> if marks >= 80: print("Distinction") >>> elif marks >= 60: print("First Division") >>> else: print("Pass")Iterative/Loop Flow
Used to repeat same statements again and again while the need to repeat is there.Looping Statements
for Loop >>> #Display natural numbers upto 4. >>> for i in range(5): >>> print(i) while Loop >>> # Print numbers upto 5. >>> count=1 >>> while count<=5: >>> print(count) >>> count+=1
1. WAP to display the sum of two numbers.
Solution:
a=int(input("Enter first number:"))
b=int(input("Enter second number:"))
s=a+b
print("The sum is ",s)
2. WAP to find the area of rectangle and circle.
Solution:
l=float(input("Enter length:"))
b=float(input("Enter breadth:"))
r=float(input("Enter radius:"))
ArR=l*b
ArC=(22/7)*r**2
print(ArR)
print(ArC)
3. WAP to find the Simple Interest.
Solution:
p=float(input("Enter Principle:"))
t=float(input("Enter Time:"))
r=float(input("Enter Rate:"))
si=(p*t*r)/100
print("The simple interest is Rs.",si)
4. WAP to convert Celsius to Fahrenheit scale of temperature.
Solution:
c=float(input("Enter Celsius:"))
f=(9/5)*c+32
print("The converted temp value is",f,"F")
5. WAP to convert days into years, months and days.
Solution:
days=int(input("Enter days:"))
years=days//365
rem_days=days%365
months=rem_days//30
final_days=rem_days%30
print(days,"days means",years,"years",months,"months",
final_days,"days") #Write in the same line
6. WAP to check if a person is eligible to vote or not.
Solution:
age=int(input("Enter age:"))
if age>=18:
print("Eligible")
else:
print("Not Eligible")
7. WAP to check if a number is even or odd.
Solution:
a=int(input("Enter a number:"))
if a%2==0:
print("Even number")
else:
print("Odd number")
8. WAP to check if a number is positive, negative or zero.
Solution:
a=int(input("Enter number:"))
if a==0:
print("Zero")
elif a>0:
print("Positive")
else:
print("Negative")
9. WAP to find the greatest among three numbers.
Solution:
a=int(input("Enter first number:"))
b=int(input("Enter second number:"))
c=int(input("Enter third number:"))
if (a>b>c):
print("Greatest number is:",a)
elif (b>a>c):
print("Greatest number is:",b)
else:
print("Greatest number is:",c)
10. WAP to find the middle number among three numbers.
Solution:
a=int(input("Enter first number:"))
b=int(input("Enter second number:"))
c=int(input("Enter third number:"))
if (a<b<c or a>b>c):
print("Middle number is:",b)
elif (b<a<c or b>a>c):
print("Middle number is:",a)
else:
print("Middle number is:",c)
11. WAP to display the first 10 natural numbers.
Solution:
for i in range(1,11):
print(i)
12. WAP to display even numbers from 200 to 300.
Solution:
for i in range(200,301,2):
print(i)
13. WAP to display odd numbers from 300 to 200.
Solution:
for i in range(299,200,-2):
print(i)
14. WAP to display the table of 21.(upto 10).
Solution:
for i in range(1,11):
print(21,"*",i,"=",21*i)
15. WAP to display the following pattern:
1
12
123
1234
12345
Solution:
for i in range(1,6):
for j in range(1,i+1):
print(j,end="")
print()
16. WAP to check if a number is a palindrome or not.
Solution:
n=int(input("Enter number:"))
z=n
s=0
while n>0:
r=n%10
s=s*10+r
n=n//10
if s==z:
print("Palindrome")
else:
print("Not Palindrome")
17. WAP to check if a number is a armstrong or not.
Solution:
n=int(input("Enter number:"))
z=n
s=0
while n>0:
r=n%10
s=s+r**3
n=n//10
if s==z:
print("Armstrong")
else:
print("Not Armstrong")
18. WAP to check if a number is a prime or composite.
Solution:
n=int(input("Enter number:"))
f=0
for i in range(1,n+1):
if (n%i==0):
f+=1
if (f==2):
print("Prime")
else:
print("Composite")
19. WAP to display the Fibonacci sequence 0,1,1,.... upto n terms.
Solution:
terms=int(input("Enter number of terms:"))
a=0 #Decide the starting point from the question
b=1 #Decide the starting point from the question
for i in range(terms):
print(a, end=" ")
c=a+b
a=b
b=c
20. WAP to display the Hailstone sequence 7,22,11,.... upto n terms.
Solution:
terms=int(input("Enter number of terms:"))
n=7 #Decide the starting point from the question
for i in range(terms):
print(n, end=" ")
if (n%2==0):
n=n//2
else:
n=3*n+1
Python Lists
A list in Python is a data type that is used to store multiple items in a single variable.Lists are:
- Ordered
- Changeable (Mutable)
- Allow duplicate values
list_name = [item1, item2, item3]
Example
fruits = ["Apple", "Mango", "Orange"]
print(fruits)
Accessing List Items
List items are accessed using index numbers. These index numbers start at 0 by default. If need be to access the list in reverse order, one can also start the indexing from -1.
fruits = ["Apple", "Mango", "Orange"]
print(fruits[0])
print(fruits[1])
print(fruits[2])
print(fruits[-1])
print(fruits[-2])
Output:
Apple
Mango
Orange
Orange
Mango
Changing List Items
fruits = ["Apple", "Mango", "Orange"]
fruits[1] = "Banana"
print(fruits)
Output:
['Apple', 'Banana', 'Orange']
Adding Items to List
(a) append() Function
The append() function adds an item at the end of the list.
fruits = ["Apple", "Mango"]
fruits.append("Orange")
print(fruits)
(b) insert() Function
The insert() function adds an item at a specific position.
fruits = ["Apple", "Mango"]
fruits.insert(1, "Banana")
print(fruits)
Removing Items from List(a) remove() Function - Remove a particular element from the list.
fruits = ["Apple", "Mango", "Orange"]
fruits.remove("Mango")
print(fruits)
(b) pop() Function
The pop() function removes item using index number.
fruits = ["Apple", "Mango", "Orange"]
fruits.pop(1)
print(fruits)
Length of List
The len() function returns the total number of items in a list.
fruits = ["Apple", "Mango", "Orange"]
print(len(fruits))
Output:
3
Looping Through a List
fruits = ["Apple", "Mango", "Orange"]
for item in fruits:
print(item)
Example Program Using List
Program: Store 5 Numbers and Find Their Sum
numbers = [10, 20, 30, 40, 50]
total=0
for i in range(len(numbers)):
total+=numbers[i]
print("Sum =", total)
Output
Sum = 150
Dictionaries in Python
DictionaryA dictionary a data type in python that is used to store data in key-value pairs.
Dictionaries are:
- Ordered
- Changeable
- Do not allow duplicate keys
dictionary_name = {
key1: value1,
key2: value2
}
Example
student = {
"name": "Ram",
"age": 15,
"grade": 10
}
print(student)
Accessing Dictionary Values
student = {
"name": "Ram",
"age": 15
}
print(student["name"])
print(student["age"])
Output:
Ram
15
Changing Dictionary Values
student = {
"name": "Ram",
"age": 15
}
student["age"] = 16
print(student)
Output:
{"name": "Ram", "age": 16}
Adding Items to Dictionary
student = {
"name": "Ram",
"age": 15
}
student["grade"] = 10
print(student)
Output:
{"name": "Ram", "age": 15, "grade": 10}
Removing Items from Dictionary
pop() Function
student = {
"name": "Ram",
"age": 15
}
student.pop("age")
print(student)
Dictionary Functions
| Function | Purpose |
|---|---|
| keys() | Returns a list of all the keys |
| values() | Returns a list of all the values |
| items() | Returns a list of all the key-value pairs |
| clear() | Removes all items |
Looping Through Dictionary
student = {
"name": "Ram",
"age": 15,
"grade": 10
}
for key, value in student.items():
print(key, ":", value)
Output:
name : Ram
age : 15
grade: 10
Example ProgramProgram: Store Student Information
student = {
"name": "Sita",
"age": 16,
"grade": 10
}
print("Name =", student["name"])
print("Age =", student["age"])
print("Grade =", student["grade"])
Output
Name = Sita
Age = 16
Grade = 10
Program: Check Whether Key Exists
student = {
"name": "Ram",
"age": 15
}
if "name" in student:
print("Key exists")
else:
print("Key does not exist")
Output:
Key exists
Difference Between List and Dictionary
| List | Dictionary |
|---|---|
| Stores items | Stores key-value pairs |
| Uses square brackets [ ] | Uses curly brackets { } |
| Accessed using index | Accessed using keys |
| Allows duplicate items | Duplicate keys not allowed |
Review Practice Programs(Lists and Dictionaries)
21. WAP to input ten numbers from the user and store them in the list. The program should then display the greatest number among ten numbers.
Solution:
num=[]
for i in range(10):
n=int(input("Enter number:"))
num.append(n)
greatest=max(num)
print("Greatest number is", greatest)
22. WAP to store five numbers in the list.
The program should then display the product of all the numbers.
Solution:
num=[]
product=1
for i in range(5):
n=int(input("Enter number:"))
num.append(n)
for i in num:
product=product*i
print("Product =", product)
23. WAP to input ten numbers from the user and store them in the list. The program should then count the even and odd numbers separately.
Solution:
num=[]
even=0
odd=0
for i in range(10):
n=int(input("Enter number:"))
num.append(n)
for i in num:
if i%2==0:
even=even+1
else:
odd=odd+1
print("Even numbers =", even)
print("Odd numbers =", odd)
24. WAP to display the longest word among three different words.
Solution:
w1=input("Enter first word:")
w2=input("Enter second word:")
w3=input("Enter third word:")
longest=w1
if len(w2)>len(longest):
longest=w2
if len(w3)>len(longest):
longest=w3
print("Longest word is", longest)
25. WAP to count the number of consonants present in the given word.
Solution:
word=input("Enter a word:").lower()
count=0
vowels="aeiou"
for ch in word:
if (ch not in vowels):
count=count+1
print("Number of consonants =", count)
26. WAP to count the number of characters N/n present in the given word.
Solution:
word=input("Enter a word:")
count=0
for ch in word:
if ch=="N" or ch=="n":
count=count+1
print("Number of N/n =", count)