Use python programming to count all unique words for all files in a given directory. the output must be words and their corresponding frequency. note: • to get all files under a directory, use os. listdir(directory name) • to check if a character is an alpha character, you can use the following example expression (3 is not a word character): o > > > str = "hello3hello" o > > > str = str. lower() # to be all lowercase first o > > > str[5] > ‘a’ and str[5] < ‘z’ o > > > false • to debug your code, create a folder with at least 3 text files. you don’t need to submit your example folder and text files.