How to substitute the concrete substring of a string in the string's list?-CodePudding

I have the following list of strings:

list_of_str = ['Notification message', 'Warning message', 'This is the |xxx - show| message.', 'Notification message is defined by |xxx - show|', 'Notification message']

How can I get the string that is closest to the tail and contains show|, and substitute show| by Placeholder|?

The expected result:

list_of_str = ['Notification message', 'Warning message', 'This is the |xxx - show| message.', 'Notification message is defined by |xxx - Placeholder|', 'Notification message']

CodePudding user response：

Reverse iteration, find and replace:

for i, s in enumerate(reversed(list_of_str), 1):
    if 'show|' in s:
        list_of_str[-i] = s.replace('show|', 'Placeholder|')
        break

CodePudding user response：

This should work

# reverse the list
for i, x in enumerate(list_of_str[::-1]):
    # replace the first instance and break loop
    if 'show|' in x:
        list_of_str[len(list_of_str)-i-1] = x.replace('show|', 'Placeholder|')
        break
list_of_str
['Notification message',
 'Warning message',
 'This is the |xxx - show| message.',
 'Notification message is defined by |xxx - Placeholder|',
 'Notification message']

CodePudding user response：

Try this:

idx = next((idx for idx in reversed(range(len(list_of_str)))
            if 'show|' in list_of_str[idx]), 0)
list_of_str[idx] = list_of_str[idx].replace('show|', 'Placeholder|')

You first find the last index containing "show|" and then you do the replacement.

Another option:

for idx in reversed(range(len(list_of_str))):
    if 'show|' in list_of_str[idx]:
        list_of_str[idx] = list_of_str[idx].replace('show|', 'Placeholder|')
        break