In CSV, how to write the header after writing the body?

[Larz60+]

You can do this:

class ChangeHeader:
    def __init__(self, file, newheader=None, newfile=None):
        self.file = file
        self.newfile = newfile
        self.nhead = newheader
        self.fix_header()

    def fix_header(self):
        addednew = False
        with open(self.file, 'r') as f, open(self.newfile, 'w') as f1:
            for line in f:
                if not addednew:
                    f1.write(self.nhead)
                    addednew = True
                else:
                    f1.write(line)

def testit():
    newhead = 'Product Name	PartDesc	Drawings	Issues	Documents'
    ChangeHeader(file='somedwgs.csv', newheader=newhead, newfile='somedwgs_new.csv')

if __name__ == '__main__':
    testit()

results:
Before:
   

after