show interfaces description cisco to txt <-> csv python

Question

I'm trying to convert from a txt file to another csv file but why can't do how can I need.

I got this txt:

Interface                      Status         Protocol Description
Gi1                            up             up       MANAGEMENT INTERFACE - DON'T TOUCH ME
Gi2                            up             up       Network Interface
Gi2.101                        up             up       mpls-subinterface-CKTx904949
Gi3                            admin down     down     Network Interface
Lo0                            up             up       
Lo56                           up             up       THIS IS A TEST LOOPBACK
Vi0                            up             up       

and this is my script:

output = open("command.txt", "r")
for line in output.readlines():
    lista = re.sub(r'\s{2,}', ";", line)
    archivo_csv = open("output-1.txt", "a")
    archivo_csv.write(lista + ";" + "\n")
    archivo_csv.close()
output.close()

output = open("output.txt", "r+")         #This second "loop" is becose between "Protocol" 
lineas =  output.readlines()              #and "Description" be only one space, the regular 
linea_1 = lineas[0]                       #expression that i did don't work for this case
lista = re.sub(r'\s+', ";", linea_1)

output.seek(0)
output.write(lista)
output.close()

vaciar_archivo = open("output.csv", "w")
vaciar_archivo.close()

output = open("output.txt", "r")
for line in output.readlines():
    lista = line
    archivo_csv = open("output.csv", "a")
    archivo_csv.write(lista)
    archivo_csv.close()
output.close()

the output is this:

Interface;Status;Protocol;Description;
;
Gi1;up;up;MANAGEMENT INTERFACE - DON'T TOUCH ME
;
Gi2;up;up;Network Interface
;
Gi2.101;up;up;mpls-subinterface-CKTx904949
;
Gi3;admin down;down;Network Interface
;
Lo0;up;up;;
Lo56;up;up;THIS IS A TEST LOOPBACK
;
Vi0;up;up;;

i can't do this well, i think that i have a problem with the form of the regular expression.

I need this so that the CSV file does not generate blank lines:

Interface;Status;Protocol;Description
Gi1;up;up;MANAGEMENT INTERFACE - DON'T TOUCH ME
Gi2;up;up;Network Interface
Gi2.101;up;up;mpls-subinterface-CKTx904949
Gi3;admin down;down;Network Interface
Lo0;up;up
Lo56;up;up;THIS IS A TEST LOOPBACK
Vi0;up;up

Could you help me improve my code?

Answer 1

You can try pandas.read_fwf:

import pandas as pd

df = pd.read_fwf("your_input_file.txt")

df["Description"] = (
    df.iloc[:, 3:].fillna("").astype(str).apply(" ".join, axis=1).str.strip()
)
df = df.iloc[:, :4]

print(df)
df.to_csv("data.csv", index=False, sep=";")

Prints:

  Interface      Status Protocol                            Description
0       Gi1          up       up  MANAGEMENT INTERFACE - DON'T TOUCH ME
1       Gi2          up       up                      Network Interface
2   Gi2.101          up       up           mpls-subinterface-CKTx904949
3       Gi3  admin down     down                      Network Interface
4       Lo0          up       up                                       
5      Lo56          up       up                THIS IS A TEST LOOPBACK
6       Vi0          up       up                                       

and saves data.csv:

Interface;Status;Protocol;Description
Gi1;up;up;MANAGEMENT INTERFACE - DON'T TOUCH ME
Gi2;up;up;Network Interface
Gi2.101;up;up;mpls-subinterface-CKTx904949
Gi3;admin down;down;Network Interface
Lo0;up;up;
Lo56;up;up;THIS IS A TEST LOOPBACK
Vi0;up;up;