multiple file input to a function(Dynamic file input) in python-CodePudding

I'm using a function which takes 3 .csv files as input to process the data in the files. The function is as follows:

def pull_data(sheet1,sheet2,sheet3, usn_number):
    # Open the first sheet
    with open(sheet1, 'r') as sheet1_file:
        sheet1_reader = csv.reader(sheet1_file)

        # Open the second sheet
        with open(sheet2, 'r') as sheet2_file:
            sheet2_reader = csv.reader(sheet2_file)

            # Open the third sheet
            with open(sheet3, 'r') as sheet3_file:
                sheet3_reader = csv.reader(sheet3_file)

                 with open(f'{group}.csv', 'w') as csv_file:
                     csv_writer = csv.writer(csv_file)
                     writer = csv.DictWriter(csv_file, fieldnames=["USN","Subject Code","Student_Name","Classes Attended","Total Classes","Attendance_Percentage"])
                     writer.writeheader()

                     for row in sheet1_reader:
                     # Check if the usn number is in the first sheet
                        if usn_number in row:
                        # If it is, add the row to the csv file
                            row.insert(1, sheet1.replace(".csv",""))
                            csv_writer.writerow(row)

                     # Loop through the second sheet
                     for row in sheet2_reader:
                     # Check if the usn number is in the second sheet
                         if usn_number in row:
                         # If it is, add the row to the csv file
                             row.insert(1, sheet2.replace(".csv",""))
                             csv_writer.writerow(row)

                     for row in sheet3_reader:
                     # Check if the usn number is in the second sheet
                         if usn_number in row:
                         # If it is, add the row to the csv file
                              row.insert(1, sheet3.replace(".csv",""))
                              csv_writer.writerow(row)

for usn in groups:
    pull_data('18MAT41.csv','18CS42.csv','18CS43.csv', usn)

How to take dynamic number of file input? like in place of 3 files i want to take n number of files dynamically.

CodePudding user response：

In python you create variadic arguments by prepending:

* (usually *args), to put the remaining positional arguments in a tuple
** (usually **kwargs), to put the remaining keyword arguments in a dict

The function definition must look like

def func(arg1, arg2, *args, kwarg1=1, kwarg2=2, **kwargs):

For a very simple example:

def concat_strings(*s):
    return "".join(s)

concat_strings("a", "b", "c")  # gives "abc"