In the previous article, we have discussed Python Program to Remove String Elements that Appear Strictly Less than k Times
Given a list, k value and the task is to delete all the elements from a given list that appears Strictly less than k times in python.
Examples:
Example1:
Input:
Given List = [2, 4, 6, 2, 3, 5, 6] Given k value = 1
Output:
The list [2, 4, 6, 2, 3, 5, 6] after deletion all the elements from a given list that appears strictly less than k times: [2, 6, 2, 6]
- Python Program to Calculate Sum of all Minimum Frequency Elements in Matrix
- Python Program to Find a Pair with the Given Sum in an Array
- Python Program to Find the Minimum Index of a Repeating Element in an Array/List
Example2:
Input:
Given List = [10, 20, 30, 40, 20, 10, 20, 10, 30] Given k value = 2
Output:
The list [10, 20, 30, 40, 20, 10, 20, 10, 30] after deletion all the elements from a given list that appears strictly less than k times: [10, 20, 20, 10, 20, 10]
Program to Remove Elements from the Array/List Which Appear Strictly Less than k Times in Python
Below are the ways to delete all the elements from a given list that appears Strictly less than k times in python:
- Using Dictionary (Hashing, User Input)
- Using Counter() function (Hashing, Static Input)
- Using Counter() function (Hashing, User Input)
- Using Counter() function (Hashing, User Input)
Method #1: Using Dictionary (Hashing, Static Input)
Approach:
- Take a dictionary and initialize it to empty using the {} or dict() say freqncyDictionary.
- Give the list as static input and store it in a variable.
- Loop in the given list using the For loop.
- Inside the For loop, Check if the list element is present in the dictionary or not using the if conditional statement and ‘in‘ keyword.
- If it is true then increment the count of the list element in the dictionary by 1.
- Else initialize the dictionary with the list element as key and value as 1.
- Give the k value as static input and store it in a variable.
- Take a new empty list say modifdlst and store it in a variable.
- Loop in the given list using the For loop.
- Check if the key in the freqncyDictionary having a value greater than k using the if conditional statement.
- If it is true then append the key value to the above declared empty list modifdlst.
- Print the list after deletion of all the elements from a given list that appears strictly less than k times.
- The Exit of the Program.
Below is the implementation:
# Take a dictionary and initialize it to empty
# using the {} or dict() say freqncyDictionary.
freqncyDictionary = {}
# Give the list as static input and store it in a variable.
gvnlst = [2, 4, 6, 2, 3, 5, 6]
# Loop in the given list using the For loop.
for i in gvnlst:
# Inside the For loop,
# Check if the list element is present in the dictionary
# or not using the if conditional statement and 'in' keyword.
if i in freqncyDictionary.keys():
# If it is true then increment the count of the list element
# in the dictionary by 1.
freqncyDictionary[i] = freqncyDictionary[i]+1
# Else initialize the dictionary with the list element as key and value as 1.
else:
freqncyDictionary[i] = 1
# Give the k value as static input and store it in a variable.
k = 1
# Take a new empty list say modifdlst and store it in a variable.
modifdlst = []
# Loop in the given list using the For loop.
for lstelmt in gvnlst:
# Check if the key in the freqncyDictionary having value greater than k
# using the if conditional statement.
if(freqncyDictionary[lstelmt] > k):
# If it is true then append the key value to the above declared empty list modifdlst.
modifdlst.append(lstelmt)
# Print the list after deletion of all the elements from a given list that appears
# Strictly less than k times.
print("The list", gvnlst,
"after deletion all the elements from a given list that appears strictly less than k times:")
print(modifdlst)
Output:
The list [2, 4, 6, 2, 3, 5, 6] after deletion all the elements from a given list that appears strictly less than k times: [2, 6, 2, 6]
Method #2: Using Dictionary (Hashing, User Input)
Approach:
- Take a dictionary and initialize it to empty using the {} or dict() say freqncyDictionary.
- Give the list as user input using the list(),map(),split(),int functions and store it in a variable.
- Loop in the given list using the For loop.
- Inside the For loop, Check if the list element is present in the dictionary or not using the if conditional statement and ‘in‘ keyword.
- If it is true then increment the count of the list element in the dictionary by 1.
- Else initialize the dictionary with the list element as key and value as 1.
- Give the k value as user input using the int(input()) function and store it in a variable.
- Take a new empty list say modifdlst and store it in a variable.
- Loop in the given list using the For loop.
- Check if the key in the freqncyDictionary having a value greater than k using the if conditional statement.
- If it is true then append the key value to the above declared empty list modifdlst.
- Print the list after deletion of all the elements from a given list that appears strictly less than k times.
- The Exit of the Program.
Below is the implementation:
# Take a dictionary and initialize it to empty
# using the {} or dict() say freqncyDictionary.
freqncyDictionary = {}
# Give the list as user input using the list(),map(),split(),int functions
# and store it in a variable.
gvnlst = list(
map(int, input('Enter some random list element separated by spaces = ').split()))
# Loop in the given list using the For loop.
for i in gvnlst:
# Inside the For loop,
# Check if the list element is present in the dictionary
# or not using the if conditional statement and 'in' keyword.
if i in freqncyDictionary.keys():
# If it is true then increment the count of the list element
# in the dictionary by 1.
freqncyDictionary[i] = freqncyDictionary[i]+1
# Else initialize the dictionary with the list element as key and value as 1.
else:
freqncyDictionary[i] = 1
# Give the k value as user input using the int(input()) function and store it in a variable.
k = int(input("Enter some random number ="))
# Take a new empty list say modifdlst and store it in a variable.
modifdlst = []
# Loop in the given list using the For loop.
for lstelmt in gvnlst:
# Check if the key in the freqncyDictionary having value greater than k
# using the if conditional statement.
if(freqncyDictionary[lstelmt] > k):
# If it is true then append the key value to the above declared empty list modifdlst.
modifdlst.append(lstelmt)
# Print the list after deletion of all the elements from a given list that appears
# Strictly less than k times.
print("The list", gvnlst,
"after deletion all the elements from a given list that appears strictly less than k times:")
print(modifdlst)
Output:
Enter some random list element separated by spaces = 10 20 30 40 20 10 20 10 30 Enter some random number =2 The list [10, 20, 30, 40, 20, 10, 20, 10, 30] after deletion all the elements from a given list that appears strictly less than k times: [10, 20, 20, 10, 20, 10]
Method #3: Using Counter() function (Hashing, Static Input)
Approach:
- Import the Counter() function from collections using the import keyword.
- Give the list as static input and store it in a variable.
- Calculate the frequency of all the given list elements using the Counter() function which returns the element and its frequency as key-value pair and store this dictionary in a variable(say freqncyDictionary)
- Give the k value as static input and store it in a variable.
- Take a new empty list say modifdlst and store it in a variable.
- Loop in the given list using the For loop.
- Check if the key in the freqncyDictionary having a value greater than k using the if conditional statement.
- If it is true then append the key value to the above declared empty list modifdlst.
- Print the list after deletion of all the elements from a given list that appears strictly less than k times.
- The Exit of the Program.
Below is the implementation:
# Import the Counter() function from collections using the import keyword.
from collections import Counter
# Give the list as static input and store it in a variable.
gvnlst = [2, 4, 6, 2, 3, 5, 6]
# Calculate the frequency of all the given list elements using the Counter()
# function which returns the element and its frequency as key-value pair
# and store this dictionary in a variable(say freqncyDictionary)
freqncyDictionary = Counter(gvnlst)
# Give the k value as static input and store it in a variable.
k = 1
# Take a new empty list say modifdlst and store it in a variable.
modifdlst = []
# Loop in the given list using the For loop.
for lstelmt in gvnlst:
# Check if the key in the freqncyDictionary having value greater than k
# using the if conditional statement.
if(freqncyDictionary[lstelmt] > k):
# If it is true then append the key value to the above declared empty list modifdlst.
modifdlst.append(lstelmt)
# Print the list after deletion of all the elements from a given list that appears
# Strictly less than k times.
print("The list", gvnlst,
"after deletion all the elements from a given list that appears strictly less than k times:")
print(modifdlst)
Output:
The list [2, 4, 6, 2, 3, 5, 6] after deletion all the elements from a given list that appears strictly less than k times: [2, 6, 2, 6]
Method #4: Using Counter() function (Hashing, User Input)
Approach:
- Import the Counter() function from collections using the import keyword.
- Give the list as user input using the list(),map(),split(),int functions and store it in a variable.
- Calculate the frequency of all the given list elements using the Counter() function which returns the element and its frequency as key-value pair and store this dictionary in a variable(say freqncyDictionary)
- Give the k value as user input using the int(input()) function and store it in a variable.
- Take a new empty list say modifdlst and store it in a variable.
- Loop in the given list using the For loop.
- Check if the key in the freqncyDictionary having a value greater than k using the if conditional statement.
- If it is true then append the key value to the above declared empty list modifdlst.
- Print the list after deletion of all the elements from a given list that appears strictly less than k times.
- The Exit of the Program.
Below is the implementation:
# Import the Counter() function from collections using the import keyword.
from collections import Counter
# Give the list as user input using the list(),map(),split(),int functions
# and store it in a variable.
gvnlst = list(
map(int, input('Enter some random list element separated by spaces = ').split()))
# Calculate the frequency of all the given list elements using the Counter()
# function which returns the element and its frequency as key-value pair
# and store this dictionary in a variable(say freqncyDictionary)
freqncyDictionary = Counter(gvnlst)
# Give the k value as user input using the int(input()) function and store it in a variable.
k = int(input("Enter some random number ="))
# Take a new empty list say modifdlst and store it in a variable.
modifdlst = []
# Loop in the given list using the For loop.
for lstelmt in gvnlst:
# Check if the key in the freqncyDictionary having value greater than k
# using the if conditional statement.
if(freqncyDictionary[lstelmt] > k):
# If it is true then append the key value to the above declared empty list modifdlst.
modifdlst.append(lstelmt)
# Print the list after deletion of all the elements from a given list that appears
# Strictly less than k times.
print("The list", gvnlst,
"after deletion all the elements from a given list that appears strictly less than k times:")
print(modifdlst)
Output:
Enter some random list element separated by spaces = 10 20 30 40 20 10 20 10 30 Enter some random number =2 The list [10, 20, 30, 40, 20, 10, 20, 10, 30] after deletion all the elements from a given list that appears strictly less than k times: [10, 20, 20, 10, 20, 10]
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