Compare two files and find the difference - pandas

Question

I have two csv files, have to find difference for both files and generate the output file in sheet1 - difference data for txt1.csv and sheet2 - difference data for txt2.csv. Kindly advise me.
Sample Input :
txt1.csv
txt2.csv
Code
with open('txt1.csv', 'r') as t1, open('txt2.csv', 'r') as t2:
fileone = t1.readlines()
filetwo = t2.readlines()
with open('update.csv', 'w') as outFile:
for line in filetwo:
if line not in fileone:
outFile.write(line)
with open('update1.csv', 'w') as outFile:
for line in fileone:
if line not in filetwo:
outFile.write(line)
Expected output:
In sheet1
In sheet2
Note :
When the input file is too large above code is executing very slow

Answer 1

You could try the following.
Dataset:
df1=pd.DataFrame({"A":[1,2,3,4],"B":[5,6,7,8]})
df2=pd.DataFrame({"A":[1, 2],"B":[2,9]})
Output1:
df1[~df1.apply(tuple,1).isin(df2.apply(tuple,1))].reset_index(drop=True)
A
0 3
1 4
Output2:
df2[~df2.apply(tuple,1).isin(df1.apply(tuple,1))].reset_index(drop=True)
A
0 8
1 9
In your case something like:
df1 = pd.read_csv("txt1.csv")
df2 = pd.read_csv("txt2.csv")
delta1 = df1[~df1.apply(tuple,1).isin(df2.apply(tuple,1))].reset_index(drop=True)
delta2 = df2[~df2.apply(tuple,1).isin(df1.apply(tuple,1))].reset_index(drop=True)
delta1.to_csv("txt1_delta.csv", index=False)
delta2.to_csv("txt2_delta.csv", index=False)
edit, or if you want to have it in Excel with multiple sheets:
pip install xlsxwriter # if required
import xlsxwriter
# Create a Pandas Excel writer using XlsxWriter as the engine.
writer = pd.ExcelWriter("your_output_excel.xlsx", engine="xlsxwriter")
# Write each dataframe to a different worksheet.
delta1.to_excel(writer, sheet_name="Delta1")
delta2.to_excel(writer, sheet_name="Delta2")
# Close the Pandas Excel writer and output the Excel file.
writer.save()