Python – 替换大于 K 的元素

给定元素列表，用给定的替换字符替换所有大于 K 的元素。

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.

方法#1：使用循环

在此，我们检查大于 K 的元素，如果找到，则将它们替换为 replace 字符，否则保留旧值。

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))

输出

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']

方法#2：使用列表推导

这是解决此问题的一种线性方法。与上面类似的方法，只使用一个衬垫。

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))

输出

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']