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I am trying to write to a csv file via the following
file = open('P:\test.csv', 'a') fieldnames = ('ItemID', 'Factor', 'FixedAmount') wr = csv.DictWriter(file, fieldnames=fieldnames) headers = dict((n, n) for n in fieldnames) wr.writerow(headers) wr.writerow({'ItemID':1, 'Factor': 2, 'FixedAmount':3}) However, when I look at the csv-file the first row is empty, the second row is my header, the third row is empty again and the fourth ow shows the entries 1,2 and 3. why does it >skip one row before it makes an entry?
EDIT: using python 3.2
265
Create an if condition to check for the need for writing headers. If headers exist no need to write headers. Empty/new CSV = write headers and you can leave out the writing header from that point on. I've gone ahead and added a section that will answer your loop question.
You can do open("data. csv", "rw") , this allows you to read and write at the same time.
In Python, while reading a CSV using the CSV module you can skip the first line using next() method.
Solution is to specify the "lineterminator" parameter in the constructor:
file = open('P:\test.csv', 'w') fields = ('ItemID', 'Factor', 'FixedAmount') wr = csv.DictWriter(file, fieldnames=fields, lineterminator = '\n') wr.writeheader() wr.writerow({'ItemID':1, 'Factor': 2, 'FixedAmount':3}) file.close() If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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