I am very new to python and I would be grateful for some guidance with the following. I have a text file with over 5 million rows and 8 columns, I am trying to add "15" to each value in column 4 only.
For example:
10 21 34 12 50 111 234 21 7
21 10 23 56 80 90 221 78 90
Would be changed to:
10 21 34 12 **65** 111 234 21 7
21 10 23 56 **95** 90 221 78 90
My script below allows me to isolate the column, but when I try to add any amount to it i return "TypeError: unsupported operand type(s) for +: 'NoneType' and 'int'"
file = open("file.txt")
column = []
for line in file:
column.append(int(line.split("\t")[3]))
print column
Any advice would be great.
try this to get you started -- there are many better ways using libraries but this will show you some better file handling basic methods anyway. works for the data you posted -- as long as the delimiter in your files is double space (" ") and that everything can be cast to an int. If not.....
Also -- note the correct way to start a script is with:
if __name__ == "__main__":
this is because you wont generally want any code to execute if you are making a library...
__author__ = 'charlie'
in_filename = "in_file.txt"
out_filename = "out_file.txt"
delimiter = " "
def main():
with open(in_filename, "r") as infile:
with open(out_filename, "w") as outfile:
for line in infile:
ldata = line.split(delimiter)
ldata[4] = str(int(ldata[4]) + 15)
outfile.write(delimiter.join(ldata))
if __name__ == "__main__":
main()
With Pandas :
import pandas as pd
df = pd.read_clipboard(header=None)
df[4] += 15
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