Python - 提取字符串直到其他字符串的所有字符出现

给定一个字符串，任务是编写一个Python程序来提取，直到找到其他字符串中的所有字符。

Input : test_str = “geeksforgeeks is best for all geeks”, check_str = “freak”

Output : geeksforgeeks is best for a

Explanation : a is last letter in freak to be present in string. The string is printed till first occurrence of a.

Input : test_str = “geeksforgeeks is best for all geeks”, check_str = “geeki”

Output : geeksforgeeks i

Explanation : i is last letter in freak to be present in string. The string is printed till first occurrence of i.

方法 #1：使用all() +切片+循环

在这种情况下，子字符串被构造到循环中的当前索引，然后从字符串，使用 all() 检查来自其他字符串的所有元素。如果全部都存在，则返回子字符串。

Python3

# Python3 code to demonstrate working of
# Extract String till all occurrence of characters from other string
# Using all() + slicing + loop
  
# initializing string
test_str = "geeksforgeeks is best for all geeks"
  
# printing original string
print("The original string is : " + str(test_str))
  
# initializing check string
check_str = "freak"
  
for idx in range(1, len(test_str)):
    temp = test_str[:idx]
  
    # checking for all chars of check_str in substring
    if all([char in temp for char in check_str]):
        res = temp
        break
  
# printing result
print("String till all characters occurred : " + str(res))

输出：

The original string is : geeksforgeeks is best for all geeks
String till all characters occurred : geeksforgeeks is best for a

方法 #2：使用find() + max() +切片

在这里，检查字符串中的每个字符都被迭代，检查所有的索引并记录其中的最大值。切片直到最大索引的子串是必需的答案。

蟒蛇3

# Python3 code to demonstrate working of
# Extract String till all occurrence of characters from other string
# Using find() + max() + slice
  
# initializing string
test_str = "geeksforgeeks is best for all geeks"
  
# printing original string
print("The original string is : " + str(test_str))
  
# initializing check string
check_str = "freak"
  
# max() find maximum index of all characters
res = test_str[:max([test_str.find(idx) for idx in check_str]) + 1]
  
# printing result
print("String till all characters occurred : " + str(res))

输出：

The original string is : geeksforgeeks is best for all geeks
String till all characters occurred : geeksforgeeks is best for a