CODEWITHSUNDEEP
pythonpandasdataframe
Vikas Gupta
Vikas Gupta

Reputation: 10904

Unable to write a new DataFrame into csv file

I am trying to write a new dataframe into the CSV file. But it is not being written into the file(empty file) neither giving any error.

I feel the issue is with this line. Since I am trying to write a single value to the column. 

order['trade_type'] = trade_type

Any idea what's wrong here. 

def write_transaction_to_file(trade_type):
    order = pd.DataFrame()
    order['trade_type'] = trade_type
    order.to_csv("open_pos.csv", sep='\t', index=False)


write_transaction_to_file('SELL')

Upvotes: 1

Views: 346

Answers (1)

Valdi_Bo
Valdi_Bo

Reputation: 30971

Your code creates an empty DataFrame, without even column names.

And now look at order['trade_type'] = trade_type.

If order contained some rows, among columns there were one named just 'trade_type' (string) and trade_type (variable) was a scalar, then in all rows in order would receive this value (in this column).

But since order contains no rows, there is no place to write to.

Instead you can append a row, e.g.:

order = order.append({'trade_type': trade_type}, ignore_index=True)

The rest of code is OK, the output file name as ordinary string is also OK.

Other solution: Just create a DataFrame with a single row and single named column, filled with your variable:

order = pd.DataFrame([[trade_type]], columns=['trade_type'])

Then write it to CSV file as before.

Upvotes: 2

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