# exp7.py3   example file  read and write files of various types

def main():
  line1 = "line1\n"  # needs  \n  new line
  line2 = "line2\n"
  line3 = "line3\n"

  print("exp73.py running")
  print("write a file  exp7file.txt")
  file7 = open("exp7file.txt","w")  # open a file for writing
  file7.write(line1)                # creates file, overwrites if exists
  file7.write(line2)
  file7.write(line3)
  file7.close()                     # close the file
  print("file written")

  print("read the entire file just written")
  inp = open("exp7file.txt","r")    # open existing file for reading
  inputs = inp.read()               # reads entire file
  inp.close()                       # close the file
  print("read from exp7file.txt file and print")
  print(inputs)

  print("read a line at a time")
  inp = open("exp7file.txt","r")    # open existing file for reading
  input1 = inp.readline()           # reads one line
  print(input1)
  input1 = inp.readline()           # reads next line
  print(input1)
  input1 = inp.readline()           # reads next line
  print(input1)
  inp.close()                       # close the file

  # read numbers from file
  print("read numbers from file  data.txt")
  with open('data.txt') as f:
    polyShape = []
    for line in f:
      line = line.split() # to deal with blank
      if line:            # lines (ie skip them)
        line = [int(i) for i in line]
        polyShape.append(line)

    print(polyShape)


if __name__ == '__main__':
  main()