Python Algorithms

Question 1

Write a Python program to print the following string in a specific format (see the output). Go to the editor
Sample String : “Twinkle, twinkle, little star, How I wonder what you are! Up above the world so high, Like a diamond in the sky. Twinkle, twinkle, little star, How I wonder what you are” Output :

Twinkle, twinkle, little star,
	How I wonder what you are! 
		Up above the world so high,   		
		Like a diamond in the sky. 
Twinkle, twinkle, little star, 
	How I wonder what you are

Answer 1

print(“Twinkle, twinkle, little star, \n\tHow I wonder what you are! \n\t\tUp above the world so high, \n\t\tLike a diamond in the sky. \nTwinkle, twinkle, little star, \n\tHow I wonder what you are!”)

Question 2

Write a Python program to get the Python version you are using.

Answer 2

import sys
print("Python version")
print (sys.version)
print("Version info.")
print (sys.version_info)

Python version
3.5.2 (default, Sep 10 2016, 08:21:44)
[GCC 5.4.0 20160609]
Version info.
sys.version_info(major=3, minor=5, micro=2, releaselevel=’final’, serial=0)

Question 3

Write a Python program to display the current date and time.
Sample Output :
Current date and time :
2014-07-05 14:34:14

Answer 3

import datetime
now = datetime.datetime.now()
print (“Current date and time : “)
print (now.strftime(“%Y-%m-%d %H:%M:%S”))

Question 4

Write a Python program which accepts the radius of a circle from the user and compute the area.

Sample Output :
r = 1.1
Area = 3.8013271108436504

Answer 4

from math import pi
r = float(input (“Input the radius of the circle : “))
print (“The area of the circle with radius “ + str(r) + “ is: “ + str(pi * r**2))

Question 5

Write a Python program which accepts the user’s first and last name and print them in reverse order with a space between them.

Answer 5

fname = input(“Input your First Name : “)
lname = input(“Input your Last Name : “)
print (“Hello “ + lname + “ “ + fname)

Question 6

Write a Python program which accepts a sequence of comma-separated numbers from user and generate a list and a tuple with those numbers.

Answer 6

values = input("Input some comma seprated numbers : ")
list = values.split(",")
tuple = tuple(list)
print('List : ',list)
print('Tuple : ',tuple)

Sample Output:
Input some comma seprated numbers : 3,5,7,23
List : [‘3’, ‘5’, ‘7’, ‘23’]
Tuple : (‘3’, ‘5’, ‘7’, ‘23’)

Question 7

Write a Python program to accept a filename from the user and print the extension of that.

Answer 7

filename = input(“Input the Filename: “)
f_extns = filename.split(“.”)
print (“The extension of the file is : “ + repr(f_extns[-1]))

Sample Output:
Input the Filename: abc.java
The extension of the file is : ‘java’

Question 8

Write a Python program to display the first and last colors from the following list.
color_list = [“Red”,”Green”,”White” ,”Black”]

Answer 8

color_list = [“Red”,”Green”,”White” ,”Black”]
print( “%s %s”%(color_list[0],color_list[-1]))

Red Black

Question 9

Write a Python program that accepts an integer (n) and computes the value of n+nn+nnn.
Sample value of n is 5
Expected Result : 615

Answer 9

a = int(input("Input an integer : "))
n1 = int( "%s" % a )
n2 = int( "%s%s" % (a,a) )
n3 = int( "%s%s%s" % (a,a,a) )
print (n1+n2+n3)

Question 10

Write a Python program to print the documents (syntax, description etc.) of Python built-in function(s).
Sample function : abs()
Expected Result :
abs(number) -> number
Return the absolute value of the argument.

Answer 10

print(abs.__doc__)

Sample Output:
Return the absolute value of the argument.

Question 11

Write a Python program to print the calendar of a given month and year.
Note : Use ‘calendar’ module.

Answer 11

import calendar
y = int(input(“Input the year : “))
m = int(input(“Input the month : “))
print(calendar.month(y, m))

Sample Output:

Input the year : 2017
Input the month : 04
April 2017
Mo Tu We Th Fr Sa Su
1 2
3 4 5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30

Question 12

Write a Python program to calculate number of days between two dates.
Sample dates : (2014, 7, 2), (2014, 7, 11)
Expected output : 9 days

Answer 12

from datetime import date
f_date = date(2014, 7, 2)
l_date = date(2014, 7, 11)
delta = l_date - f_date
print(delta.days)

Sample Output:
9

Question 13

Write a Python program to get the volume of a sphere with radius 6.

Answer 13

volume = 4/3pi * r^3
pi = 3.1415926535897931
r= 6.0
V= 4.0/3.0*pi* r**3
print('The volume of the sphere is: ',V)

Sample Output:
The volume of the sphere is: 904.7786842338603

Question 14

Write a Python program to get the difference between a given number and 17, if the number is greater than 17 return double the absolute difference.

Answer 14

def difference(n):
    if n <= 17:
        return 17 - n
    else:
        return (n - 17) * 2

print(difference(22))
print(difference(14))

Sample Output:
10
3

Question 15

Write a Python program to test whether a number is within 100 of 1000 or 2000

Answer 15

def near_thousand(n):
      return ((abs(1000 - n) <= 100) or (abs(2000 - n) <= 100))
print(near_thousand(1000))
print(near_thousand(900))
print(near_thousand(800))
print(near_thousand(2200))

Sample Output:

Question 16

Write a Python program to calculate the sum of three given numbers, if the values are equal then return thrice of their sum.

Answer 16

def sum_thrice(x, y, z):

 sum = x + y + z

 if x == y == z:
  sum = sum * 3
 return sum

print(sum_thrice(1, 2, 3))
print(sum_thrice(3, 3, 3))

Sample Output:
6
27

Question 17

Write a Python program to get a new string from a given string where “Is” has been added to the front. If the given string already begins with “Is” then return the string unchanged.

Answer 17

def new_string(str):
  if len(str) >= 2 and str[:2] == "Is":
    return str
  return "Is" + str

print(new_string("Array"))
print(new_string("IsEmpty"))

Sample Output:
IsArray
IsEmpty

Question 18

Write a Python program to get a string which is n (non-negative integer) copies of a given string.

Answer 18

def larger_string(str, n):
   result = ""
   for i in range(n):
      result = result + str
   return result

print(larger_string(‘abc’, 2))
print(larger_string(‘.py’, 3))

Sample Output:
abcabc
.py.py.py

Question 19

Write a Python program to find whether a given number (accept from the user) is even or odd, print out an appropriate message to the user.

Answer 19

num = int(input("Enter a number: "))
mod = num % 2
if mod > 0:
    print("This is an odd number.")
else:
    print("This is an even number.")

Sample Output:
Enter a number: 5
This is an odd number.

Question 20

Write a Python program to count the number 4 in a given list.

Answer 20

def list_count_4(nums):
  count = 0
  for num in nums:
    if num == 4:
      count = count + 1

return count

print(list_count_4([1, 4, 6, 7, 4]))
print(list_count_4([1, 4, 6, 4, 7, 4]))

Sample Output:
2
3

Question 21

Write a Python program to get the n (non-negative integer) copies of the first 2 characters of a given string. Return the n copies of the whole string if the length is less than 2

Answer 21

def substring_copy(str, n):
  flen = 2
  if flen > len(str):
    flen = len(str)
  substr = str[:flen]

  result = ""
  for i in range(n):
    result = result + substr
  return result
print(substring_copy('abcdef', 2))
print(substring_copy('p', 3));

Sample Output:
abab
ppp

Question 22

Write a Python program to test whether a passed letter is a vowel or not.

Answer 22

def is_vowel(char):
    all_vowels = 'aeiou'
    return char in all_vowels
print(is_vowel('c'))
print(is_vowel('e'))

Sample Output:
False
True

Question 23

Write a Python program to check whether a specified value is contained in a group of values.

Test Data :
3 -> [1, 5, 8, 3] : True
-1 -> [1, 5, 8, 3] : False

Answer 23

def is_group_member(group_data, n):
    for value in group_data:
        if n == value:
            return True
    return False
print(is_group_member([1, 5, 8, 3], 3))
print(is_group_member([5, 8, 3], -1))

Sample Output:
True
False

Question 24

Write a Python program to create a histogram from a given list of integers.

Answer 24

def histogram( items ):
    for n in items:
        output = ''
        times = n
        while( times > 0 ):
          output += '*'
          times = times - 1
        print(output)

histogram([2, 3, 6, 5])

Sample Output:

• **

Question 25

Write a Python program to concatenate all elements in a list into a string and return it.

Answer 25

``` def concatenate_list_data(list): result= '' for element in list: result += str(element) return result ``` print(concatenate_list_data([1, 5, 12, 2])) Sample Output: 15122

Question 26

Write a Python program to print all even numbers from a given numbers list in the same order and stop the printing if any numbers that come after 237 in the sequence. numbers = [ 386, 462, 47, 418, 907, 344, 236, 375, 823, 566, 597, 978, 328, 615, 953, 345, 399, 162, 758, 219, 918, 237, 412, 566, 826, 248, 866, 950, 626, 949, 687, 217, 815, 67, 104, 58, 512, 24, 892, 894, 767, 553, 81, 379, 843, 831, 445, 742, 717, 958,743, 527 ]

Answer 26

``` for x in numbers: if x == 237: print(x) break; elif x % 2 == 0: print(x) ``` Sample Output: 386 462 418 344 236 566 978 328 162 758 918 237

Question 27

Write a Python program to print out a set containing all the colors from color_list_1 which are not present in color_list_2. ``` Test Data : color_list_1 = set(["White", "Black", "Red"]) color_list_2 = set(["Red", "Green"]) Expected Output : {'Black', 'White'} ```

Answer 27

``` Test Data : color_list_1 = set(["White", "Black", "Red"]) color_list_2 = set(["Red", "Green"]) Expected Output : {'Black', 'White'} ``` Sample Output: {'White', 'Black'}

Question 28

Write a Python program that will accept the base and height of a triangle and compute the area.

Answer 28

``` b = int(input("Input the base : ")) h = int(input("Input the height : ")) ``` ``` area = b*h/2 print("area = ", area) ``` Sample Output: Input the base : 20 Input the height : 40 area = 400.0

Question 29

Create a function that accepts a number as an input. Return a new array that counts down by one, from the number (as arrays 'zero'th element) down to 0 (as the last element). For example countDown(5) should return [5,4,3,2,1,0].

Answer 29

``` myarr = [] def countDown(num): while (num >=0): myarr.append(num) num =num - 1 print(myarr) ``` countDown(15) Output: [15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0]

Question 30

Print and Return - Your function will receive an array with two numbers. Print the first value, and return the second.

Answer 30

``` def print1returnanother(a,b): print(a) return(b) ``` print1returnanother(5,7) Output: 5

Question 31

ForThis Length, That Value - Write a function called lengthAndValue which accepts two parameters, size and value. This function should take two numbers and return a list of length size containing only the number in value. For example, lengthAndValue(4,7) should return [7,7,7,7]

Answer 31

``` def lengthandvalue(size, value): arr = [] i = 0 while i < size: arr.append(value) i += 1 return arr ``` print(lengthandvalue(7,7)) Output: [7, 7, 7, 7, 7, 7, 7]