#Write a function called "replace_all" that accepts three #arguments: # # - target_string, a string in which to search. # - find_string, a string to search for. # - replace_string, a string to use to replace every instance # of the value of find. # #The arguments will be provided in this order. Your function #should mimic the behavior of "replace", but you cannot use #that function in your implementation. Instead, you should #find the result using a combination of split() and join(), #or some other method. # #Hint: This exercise can be complicated, but it can also #be done in a single short line of code! Think carefully about #the methods we've covered. #Write your function here!

Here is the function replace_all:

def replace_all(target_string,find_string,replace_string):

   result_string = replace_string.join(target_string.split(find_string))  

   return result_string

#if you want to see the working of this function then you can call this function using the following statements:

target_string = "In case I don't see ya, good afternoon, good evening, and good night!"

find_string = "good"

replace_string = "bad"

print(replace_all(target_string, find_string, replace_string)

Explanation:

The above program has a function called replace_all that accepts three arguments i.e target_string, a string in which to search ,find_string, a string to search for and replace_string, a string to use to replace every instance of the value of find_string. The function has the following statement:

replace_string.join(target_string.split(find_string))  

split() method in the above statement is splits or breaks the target_string in to a list of strings based on find_string. Here find_string is passed to split() method as a parameter which works as a separator. For example above:

target_string = In case I don't see ya, good afternoon, good evening, and good night!

find_string = good

After using target_string.split(find_string) we get:

["In case I don't see ya, ", ' afternoon, ', ' evening, and ', ' night']

Next join() method is used to return a string concatenated with the elements of target_string.split(find_string). Here join takes the list ["In case I don't see ya, ", ' afternoon, ', ' evening, and ', ' night'] as parameter and joins elements of this list by 'bad'.

replace_string = bad

After using replace_string.join(target_string.split(find_string))  we get:

In case I don't see ya, bad afternoon, bad evening, and bad night!  

The program and output is attached as a screenshot.