如何读取具有分组数据且每组具有不同列的 CSV？

Question

I have just started learning Python. In the same context, I have got an assignment to parse a CSV and compare with another which is in the same format.

CSV can be read as:

"first-report","10/01/2019 at  18:54:55"
"Tags Company","B2 603, Belcastel","MV Street, (near Orbis School - 2)","Pune","Maharashtra","India","1"
"James Kooney","sants_rn","Manager"
"Groups","IPs","Hosts","Hosts Matching Filters","Analysis","Date Range","Network","Tags"
"null","NONE","0","0","scans","N/A","ALL","NONE"

"Total Vulnerabilities","Avg Risk","Business Risk"
"17","2.8","14/100"

"IP","Network","Total Vulnerabilities","Security Risk"
"10.10.10.10","Global Default Network","17","2.8"

by Status
"Status","Confirmed","Potential","Total"
"New","1","3","4"
"Active","0","0","0"
"Re-Opened","0","0","0"
"Total","1","3","4"
"Fixed","0","0","0"
"Changed","1","3","4"

As it is portrayed in sample data, CSV doesnot have fixed columns. Data is segregated in different groups. I want to compare the following keys from groups from the aforementioned CSV and print out the differences in a summary file wherever there is a mismatch in key-values. Eg Difference found at line 14, Expected "New" found "Active"

"Groups","IPs","Hosts","Hosts Matching Filters","Analysis","Date Range","Network","Tags"
"Total Vulnerabilities","Avg Risk","Business Risk"
"IP","Network","Total Vulnerabilities","Security Risk"
"Status","Confirmed","Potential","Total"

Can someone please guide me for the optimum solution.

I was struggling with finding different options but no luck so far. My approach was using CSV.DictReader to compare each key, however, because of the variable column count, I am facing some indexing issues.

Here is the sample code which I have written.

    summary = open(summary, 'w')
    actualcsvdict = csv.DictReader(open(actualoutput), fieldnames=fieldnames)
    exxpectedcsvdict = csv.DictReader(open(expectedoutput), fieldnames=fieldnames)

    actualcsvrows = list(actualcsvdict)
    expectedcsvrows = list(exxpectedcsvdict)
    print(len(actualcsvrows))
    for line in range(len(actualcsvrows)):
        if actualcsvrows[line] != expectedcsvrows[line]:
            summary.write(f"\nMismatch found at line number {line + 2}\n")
            for key1 in actualcsvrows[line]:
                if actualcsvrows[line][key1] != expectedcsvrows[line][key1]:
                    summary.write(
                        f"For {key1} column, Expected value was[ {actualcsvrows[line][key1]} ] Found [ {expectedcsvrows[line][key1]} ]\n")

PS fieldnames in this case is

"Status","Confirmed","Potential","Total"

Answer 1

For your specific case, you don't need to use the DictReader class, the normal reader class is enough.

summary = open(summary, 'w')
actualcsv = csv.reader(open(actualoutput))
exxpectedcsv = csv.reader(open(expectedoutput))

actualrows = list(actualcsv)
expectedrows = list(exxpectedcsv)
for line in range(len(actualrows)):
    if actualrows[line] != expectedrows[line]:
        summary.write(f"\nMismatch found at line number {line + 2}\n")
        for act,exp in zip(actualrows[line], expectedrows[line]):
            if act != exp:
                summary.write(f"Expected {exp}, got {act}\n")

But to be honest, I think your problem could get solved by the difflib library, depending on your exact needs.