In this article, we will be understanding the functionality of Python replace() function.
Python replace() function with String
Python has in-built string.replace() function to replace a porting of a string with another string.
string.replace() function accepts the string to be replaced and the new string which u want to replace the old string with.
string.replace("old string","new string", count)
old string: The string to be replaced.
new string: The new portion of the string that you wish to place in the old string’s position.
count: It represents the number of times, we want the string to be replaced by the new string.
Example 1: Replacing old string with a new string passed to the function
inp_str = "Python with AskPython" res = inp_str.replace("AskPython", "AP") print("Original String:",inp_str) print("Replaced String:",res)
In the above snippet of code, we have replaced the string – ‘AskPython’ with ‘AP’.
Original String: Python with AskPython Replaced String: Python with AP
Replacing Specified Number of Instances
Now let’s use the count parameter to specify the number of instances of a string that we want to replace.
Example 2: Using
count as a parameter to the replace() function
inp_str = "abcdaaseweraa" res = inp_str.replace("a", "x",2) print("Original String:",inp_str) print("Replaced String:",res)
In this example, we have passed the input string as – ‘abcdaaseweraa’. Further, we have passed the character ‘a’ of the original string to be replaced by the character ‘x’.
Here, the count is set to 2 i.e. only the first two encountered character ‘a’ will be replaced by the character ‘x’. The remaining encountered ‘a’ will be unlaterted and will remain the same.
Original String: abcdaaseweraa Replaced String: xbcdxaseweraa
Python replace() function with Pandas module
The replace() function can also be used to replace some string present in a csv or text file.
Python Pandas module is useful when it comes to dealing with data sets. The
pandas.str.replace() function is used to replace a string with another string in a variable or data column.
dataframe.str.replace('old string', 'new string')
We will be using the following data set in the below example:
import pandas df = pandas.read_csv("C:/IMDB_data.csv", sep=",",encoding='iso-8859-1') df['Language']=df['Language'].str.replace("English","Hindi")
In the above snippet of code,
pandas.read_csv() function is used to import and load a dataset.
As seen above in the data set, we have selected the ‘Language’ column in order to replace ‘English’ with ‘Hindi’.
So, as we have seen above, the Python replace() function is very useful when it comes to replacing a portion of a string for a huge data set.
I would strongly recommend the readers to go through the Pandas tutorial to learn further about how to interact with CSV files in Python.
- Python replace() function article on JournalDev