Python File Exists API
The operating system (os) module has a sub module by the name 'path' that contains a method isfile(). This method can be used to know whether a file that we are opening really exists or not.
For example, os.path.isfile(fname) gives True if the file exists otherwise False. We can use it as:
if os.path.isfile(fname): #if file exists, f = open(fname, 'r') #open it else: print(fname+' does not exist') sys.exit() #terminate the program
Example for Python File Exists API
import os, sys fname = input('Enter filename:') if os.path.isfile(fname): f = open(fname, 'r') else: print(fname+' does not exist') sys.exit() print('The file contents are:') str = f.read() print(str) f.close()
Python program to count number of lines, words and characters in a text file
import os, sys fname = input('Enter filename:') if os.path.isfile(fname): f = open(fname, 'r') else: print(fname+' does not exist') sys.exit() cl= cw= cc = 0 for line in f: words = line.split() cl +=1 cw += len(words) cc += len(line) print('No. of lines:', cl) print('No. of words:', cw) print('No. of characters:', cc) f.close()