Below is the code that worked for me:
import os, zipfile
dir_name = 'C:\\SomeDirectory'
extension = ".zip"
os.chdir(dir_name) # change directory from working dir to dir with files
for item in os.listdir(dir_name): # loop through items in dir
if item.endswith(extension): # check for ".zip" extension
file_name = os.path.abspath(item) # get full path of files
zip_ref = zipfile.ZipFile(file_name) # create zipfile object
zip_ref.extractall(dir_name) # extract file to dir
zip_ref.close() # close file
os.remove(file_name) # delete zipped file
Looking back at the code I had amended, the directory was getting confused with the directory of the script.
The following also works while not ruining the working directory. First remove the line
os.chdir(dir_name) # change directory from working dir to dir with files
Then assign file_name as
file_name = dir_name + "/" + item
