Python – 每第 K 个字符串大写

给定一个字符串列表，将每个第 K 个字符串更改为大写。

Input : test_list = [“gfg”, “is”, “best”, “for”, “geeks”], K = 3
Output : [‘GFG’, ‘is’, ‘best’, ‘FOR’, ‘geeks’]
Explanation : All Kth strings are uppercased.

Input : test_list = [“gfg”, “is”, “best”, “for”, “geeks”], K = 4
Output : [‘GFG’, ‘is’, ‘best’, ‘for’, ‘GEEKS’]
Explanation : All Kth strings are uppercased.

方法＃1：使用循环+上（）

在此，我们使用循环对所有字符串进行迭代，并且使用大写来执行大写，使用模运算符检测第 K 个索引。

Python3

# Python3 code to demonstrate working of 
# Every Kth Strings Uppercase
# Using loop + upper()
  
# initializing list
test_list = ["gfg", "is", "best", "for", "geeks", "and", "CS"] 
  
# printing original list
print("The original list is : " + str(test_list))
  
# initializing K 
K = 3
  
res = []
for idx in range(len(test_list)):
      
    # checking for Kth index
    if idx % K == 0:
        res.append(test_list[idx].upper())
    else :
        res.append(test_list[idx])
  
# printing result 
print("The resultant String list : " + str(res))

输出

The original list is : ['gfg', 'is', 'best', 'for', 'geeks', 'and', 'CS']
The resultant String list : ['GFG', 'is', 'best', 'FOR', 'geeks', 'and', 'CS']

方法#2：使用列表推导

这是可以执行此任务的另一种方式。在此我们使用列表推导作为简写，执行类似于上述方法的任务。

Python3

# Python3 code to demonstrate working of 
# Every Kth Strings Uppercase
# Using list comprehension
  
# initializing list
test_list = ["gfg", "is", "best", "for", "geeks", "and", "CS"] 
  
# printing original list
print("The original list is : " + str(test_list))
  
# initializing K 
K = 3
  
# shorthand to perform this task
res = [test_list[idx].upper() if idx % K == 0 else test_list[idx]
       for idx in range(len(test_list))]
  
# printing result 
print("The resultant String list : " + str(res))

输出

The original list is : ['gfg', 'is', 'best', 'for', 'geeks', 'and', 'CS']
The resultant String list : ['GFG', 'is', 'best', 'FOR', 'geeks', 'and', 'CS']