Adding a header to multiple csv files

Question

Can anyone guide me on how to add a header to multiple csv files?

Optional: If anyone knows a method add add a header to pre-existing files in C# or can guide me to the relevant resources. That would be great.

import os
import os.path as path

## First create a function that will generate random files.
def create_random_csv_files(fault_classes, number_of_files_in_each_class):
    os.mkdir("./random_data/")  # Make a directory to save created files.
    for fault_class in fault_classes:
        for i in range(number_of_files_in_each_class):
            data = np.random.rand(1024,3)
            file_name = "./random_data/" + eval("fault_class") + "_" + "{0:03}".format(i+1) + ".csv" # This creates file_name
            np.savetxt(eval("file_name"), data, delimiter = ",", comments = "")
        print(str(eval("number_of_files_in_each_class")) + " " + eval("fault_class") + " files"  + " created.")

Answer 1

import os
import os.path as path

## First create a function that will generate random files.
def create_random_csv_files(fault_classes, number_of_files_in_each_class):
    os.mkdir("./random_data/")  # Make a directory to save created files.
    for fault_class in fault_classes:
        for i in range(number_of_files_in_each_class):
            data = np.random.rand(1024,3)
            file_name = "./random_data/" + eval("fault_class") + "_" + "{0:03}".format(i+1) + ".csv" # This creates file_name
            np.savetxt("file_name", data, delimiter = ",", header = "V1,V2,V3", comments = "")
        print(str("number_of_files_in_each_class") + " " + "fault_class" + " files"  + " created.")