combining two csv files python

Question

I have data stored in two different CSV files. I want to dump file b at the end of file a and also I want to remove the header ie, first line of file b. I can combine two files using open('final.csv', 'a') but that also includes header of file b. Any help will be greatly appreciated.

Answer 1

I'm assuming you want to know how to skip the header when reading a file, since you don't specify how exactly the two files are to be appended (in-memory, on the file system, ... ?).

After opening the file, you can use next() on the file object to skip ahead one line, like so:

with open("file_b", "r") as fb:
    next(fb) # skip 1 line
    for line in fb:
        # do whatever you want with the remaining lines, e.g. append them
        # to file_a

Alternatively, because you had "numpy" as a question tag earlier, you can use numpy's loadtxt() function, which has a parameter called skiprows that can be used to do what you want. Just open file_b like so:

with open("file_b", "r") as fb:
    all_lines_except_header = numpy.loadtxt(fb, skiprows=1)

This will also parse the CSV file, however. If you're only interested in lines and not in individual fields, I would recommend the first method.