How do I swap two items in a file which contains words on the left and numbers on the right?

I want to achieve numbers on the right and strings on the left.

I have a text file that contains huge numbers i.e corpus:

200 Apple
200 Banana
1 Hi
1 Hello
1112 Elevator

CodePudding user response：

1. open file f for reading
2. open file g for writing
3. loop over all lines in file f:
   • split the line at the first space into parts a and b
   • concatenate parts b and a in swapped order with a space in between
   • write concatenated line to file g
4. close files f and g

CodePudding user response：

You can do this in 3 clean steps with a pandas dataframe.

1. read file
2. swap columns
3. write new file

so the code looks like this:

import pandas as pd

# read into dataframe
data = pd.read_csv("some_file.txt", delimiter=" ", header=None)

# swap columns
data[0], data[1] = data[1], data[0]

# write data to a new file
data.to_csv("some_file_new.txt", header=False, index=False, sep = ' ')


print('file written !!')

and the new file contents looks like this:

Apple 200
Banana 200
Hi 1
Hello 1
Elevator 1112