Line split problem (beginner)

Data=io.open(filename, mode='r').readlines()
NewData=open(filename,'w')
for Line in Data :
  for Item in Line :
    NewData.write(Item+'\n')
NewData.close()

# an approach using split.

# the with statement handles errors and closes the file.
with open('in', mode='r') as input_stream:
    Data = input_stream.readlines()

# remove first line if it was really as you say
discard = "'INPUT FILE'"
if Data[0].startswith(discard):
    del Data[0]

with open('out.split', mode='w') as output_stream:
    output_stream.write("'OUTPUT FILE'\n")
    for line in Data:
        output_stream.write('\n'.join(line.split())+'\n')

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# More efficient solution.  Replace the spaces with new lines.
with open('in', mode='r') as input_stream:
    Data = input_stream.read()

# remove first line if it was really as you say
discard = "'INPUT FILE'\n"
i = 0
if Data.startswith(discard):
    i = len(discard)

with open('out.replace', mode='w') as output_stream:
    output_stream.write("'OUTPUT FILE'\n")
    output_stream.write(Data[i:].replace(' ','\n'))