Author
Abhinav Rawat
Product Manager @ Interview Kickstart | Ex-upGrad | BITS Pilani. Working with hiring managers from top companies like Meta, Apple, Google, Amazon etc to build structured interview process BootCamps across domains
In most software engineering interview problems, string handling can become a tedious task. Both Python and Java language provide some well-defined library functions that can make working with strings easy. Python’s string replace() method is one such built-in function, and we will cover the details of it in this article:
Python’s string replace() method is a built-in function that returns a copy of a string, where all occurrences of a substring are replaced with another substring.
Syntax of the replace() method:
Parameters of the replace() method:
count is an optional parameter; if not specified, all the occurrences of the old substring are replaced with the new substring.
The replace() method returns a copy of the string where the old substring is replaced with the new substring. The original string is unchanged. If the old substring is not found, it returns the copy of the original string.
Let’s create a file named “replace.py†and assign a variable â€input_string†to the string mentioned below:
input_string = “Thor was more powerful.Thor was the most popular of all the gods. Thor was a god of war and lightning.”
print(input_string.replace(“Thor”,”Loki”))
Output: “Loki was more powerful.Loki was the most popular of all the gods. Loki was a god of war and lightning.â€
Note: In this example, we have not used the count parameter. If count is not specified, all the occurrences of the old substring are replaced with the new substring. In this case, three occurrences of the word “Thor†are replaced by â€Loki.â€
Let’s create a file named “replaceWithCount.py†and assign a variable â€input_string†to the string mentioned below:
input_string = “Thor was the most popular of all the gods. Thor was a god of war and lightning. Thor was physically strong.”
print(input_string.replace(“Thor”,”Loki”,2))
In this example, we use the count parameter. The input string contains three occurrences of “Thor.†We only want to change the first two occurrences of it. So, we pass 2 as the value of the count parameter.
Output: “Loki was the most popular of all the gods. Loki was a god of war and lightning. Thor was physically strong.â€
Note: If we pass count value as 0, there will be no change in the original string.
input_string = “Thor was the most popular of all the gods. Thor was a god of war and lightning. Thor was physically strong.”
print(input_string.replace(“Thor”,”Loki”,0))
â€Output: “Thor was the most popular of all the gods. Thor was a god of war and lightning. Thor was physically strong.â€
In this example, we save a string in a file. Then we read the file and replace all occurrences of “Thor†with “Loki.â€
input_string = input()
delimiter = “Thor”
new_delimiter = “Loki”
modified_string = input_string.replace(delimiter , new_delimiter)
print(“modified_string =”, modified_string)
Following are some escape characters and how you can use them in code:
input_string = “This is backslash /”
print(input_string.replace(“/”,”//”))
â€Output: This is backslash //
input_string= “here’s doublequote”
print(input_string.replace(” “, “””))
Output: here’sâ€doublequote
Question 1: If Strings are immutable
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