# Author:  James Tam
# Version: March 28, 2018
#
# Learning objectives:
# * File input error handling using exceptions: empty file name,
#   empty file

fileOK = False
while (fileOK == False):
    filename = input("Enter name of file: ")
    # JT: the following two IF-constructs check for the same
    # thing  both are included to illustrate two equally correct
    # ways of checking.
    if (filename == ""):
        print("File name cannot be blank")

    # Equally valid alternative
    # if (len(filename) == 0):
    #    print("File name cannot be blank")
    
    # If name not blank, try to open file
    else:   
        try:
            inputFile = open(filename,"r")
            line = inputFile.readline()
            # Tried to read line from newly opened file, 
            # if string is empty then the file must be empty
            if (len(line) == 0):
                print("File %s is empty" %filename)
            else:
                while (len(line) > 0):
                    print(line)
                    line = inputFile.readline()
                fileOK = True
                inputFile.close()
        except IOError:
            print("Error cannot open %s" %filename)