如何有效地用其他元素替换字符串中的多个元素？

Question

Given a string, say 'ABCD' and you are supposed to replace 'A' and 'C' with 'E' and 'J'. How would you replace this and return the output as a string in python?

Answer 1

Using the replace() method

string = 'ABCD'
#Use dictionary of characters to be replaced
chars_to_replace = {
    'A':'E',
    'C':'J'
}
for key, value in chars_to_replace.items():
    # Use the replace() method
    string = string.replace(key, value)
print(string)

Using a for loop

string = "ABCD"
chars_to_replace = {
    'A':'E',
    'C':'J'
}
new_string = ''
# Use for loop to iterate over all chars in string
for i in string:
    # Check if character is in dict key
    if i in chars_to_replace.keys():
        # If yes, replace values of those chars
        # and add to new_string
        new_string += chars_to_replace[i]
    else:
        # If not, just add them to new_string
        new_string += i
print(new_string)

Answer 2

Use str.translate() method :

string = 'ABCD'
m = str.maketrans({'A': 'E', 'C': 'J'})

print(string.translate(m))

output :

EBJD