Python - 提取字符串列表中以 K 开头的单词

给定短语列表，提取所有以字符K 开头的字符串。

Input : test_list = [“Gfg is good for learning”, “Gfg is for geeks”, “I love G4G”], K = l
Output : [‘learning’, ‘love’]
Explanation : All elements with L as starting letter are extracted.

Input : test_list = [“Gfg is good for learning”, “Gfg is for geeks”, “I love G4G”], K = m
Output : []
Explanation : No words started from “m” hence no word extracted.

方法 #1：使用循环 + split()

这是可以解决此问题的粗暴方式。在这里，我们将每个短语转换为单词列表，然后对于每个单词，检查它的初始字符是否为 K。

Python3

# Python3 code to demonstrate working of 
# Extract words starting with K in String List
# Using loop + split()
  
# initializing list
test_list = ["Gfg is best", "Gfg is for geeks", "I love G4G"] 
  
# printing original list
print("The original list is : " + str(test_list))
  
# initializing K 
K = "g"
  
res = []
for sub in test_list:
    # splitting phrases
    temp = sub.split()
    for ele in temp:
          
        # checking for matching elements
        if ele[0].lower() == K.lower():
            res.append(ele)
  
# printing result 
print("The filtered elements : " + str(res))

输出

The original list is : ['Gfg is best', 'Gfg is for geeks', 'I love G4G']
The filtered elements : ['Gfg', 'Gfg', 'geeks', 'G4G']

方法 #2：使用列表理解 + split()

这是可以执行此任务的另一种方式。在此我们在单个列表理解中运行双嵌套循环并执行所需的条件检查。

Python3

# Python3 code to demonstrate working of 
# Extract words starting with K in String List
# Using list comprehension + split() 
  
# initializing list
test_list = ["Gfg is best", "Gfg is for geeks", "I love G4G"] 
  
# printing original list
print("The original list is : " + str(test_list))
  
# initializing K 
K = "g"
res = [ele for temp in test_list for ele in temp.split() if ele[0].lower() == K.lower()]
  
# printing result 
print("The filtered elements : " + str(res))

输出

The original list is : ['Gfg is best', 'Gfg is for geeks', 'I love G4G']
The filtered elements : ['Gfg', 'Gfg', 'geeks', 'G4G']