# File_IO_Demo_Read_File.py
#
# Anne Lavergne
# July 2015 - Modified March 2017
#
# Either ask user for a filename (and perhaps also a path)
# or
# set your filename variables once at the top of your program
# Why?

inputFile = 'words_7_a.txt'

# Demo 1 - Reading a line at a time from a file
print("\nDemo 1 - Reading a line at a time from a file.")

# Opening a file for reading
fileR = open(inputFile, 'r')

# Read its first line -> a string
firstLine = fileR.readline()
print("First line: " , firstLine)
print("Data type of variable containing the first line is: ", type(firstLine))

# Read its second line
# file object keeps track of where it currently is in the file
secondLine = fileR.readline()
print("\nSecond line: " , secondLine)

# Close the file
fileR.close( )


#--------------------------------------
# Demo 2 - Reading a line at a time from a file into a string
print("\nDemo 2 - Reading a line at a time from a file.")

# Opening a file for reading
fileR = open(inputFile, 'r')

# Read a line at a time using a for loop
for line in fileR:
    print("\nThe line read from the file is '{}'.".format(line))
    print("Data type of variable containing a line is: ", type(line))
    strippedLine = line.strip()
    print("The line once stripped is '{}'.".format(strippedLine))

# Close the file
fileR.close( )


#--------------------------------------
# Demo 3 - Reading all lines from a file into a list
print("\nDemo 3 - Reading all lines from a file into a list.")

# Opening a file for reading
fileR = open(inputFile, 'r')

# Read all lines from a file into a list
myList1 = list(fileR)
print("\nFirst list: ", myList1)
print("Data type of variable containing all lines form file: ", type(myList1))

# Close the file
fileR.close( )

#--------------------------------------
# Demo 4 - Reading all lines from a file into a list
print("\nDemo 4 - Reading all lines from a file into a list.")

# Opening a file for reading
fileR = open(inputFile, 'r')

# Read all lines from a file into a list
myList2 = fileR.readlines( )
print("\nsecond list: ", myList2)
print("Data type of variable containing all lines form file: ", type(myList2))

# Close the file
fileR.close( )