Python – Replace Elements greater than K

Given element list, replace all elements greater than K with given replace character.

Input : test_list = [3, 4, 7, 5, 6, 7], K = 5, repl_chr = None
Output : [3, 4, None, 5, None, None]
Explanation : Characters are replaced by None, greater than 5.

Input : test_list = [3, 4, 7, 5, 6, 7], K = 4, repl_chr = None
Output : [3, 4, None, None, None, None]
Explanation : Characters are replaced by None, greater than 4.

Method #1 : Using loop

In this, we check for elements greater than K, if found, they are replaced by replace character, otherwise old value is retained.

Python3

# Python3 code to demonstrate working of
# Replace Elements greater than K
# Using loop

# initializing list
test_list = [3, 4, 7, 5, 6, 7, 3, 4, 6, 9]

# printing original list
print("The original list is : " + str(test_list))

# initializing K
K = 5

# initializing repl_chr
repl_chr = "NA"

res = []
for ele in test_list:

    # replace if greater than K
    if ele > K :
        res.append(repl_chr)
    else :
        res.append(ele)

# printing result
print("The replaced list : " + str(res))

Output

The original list is : [3, 4, 7, 5, 6, 7, 3, 4, 6, 9]
The replaced list : [3, 4, 'NA', 5, 'NA', 'NA', 3, 4, 'NA', 'NA']

Method #2 : Using list comprehension

This is one liner way to solve this problem. Similar method as above, just using one liner.

Python3

# Python3 code to demonstrate working of
# Replace Elements greater than K
# Using list comprehension

# initializing list
test_list = [3, 4, 7, 5, 6, 7, 3, 4, 6, 9]

# printing original list
print("The original list is : " + str(test_list))

# initializing K
K = 5

# initializing repl_chr
repl_chr = "NA"

# one liner to solve problem
res = [repl_chr if ele > K else ele for ele in test_list]

# printing result
print("The replaced list : " + str(res))

Output

The original list is : [3, 4, 7, 5, 6, 7, 3, 4, 6, 9]
The replaced list : [3, 4, 'NA', 5, 'NA', 'NA', 3, 4, 'NA', 'NA']