Writing to CSV in Python- Rows inserted out of place-CodePudding

I have a function that writes a set of information in rows to a CSV file in Python. The function is supposed to append the file with the new row, however I am finding that sometimes it misbehaves and places the new row in a separate space of the CSV (please see picture as an example).

Whenever I reformat the data manually I delete all of the empty cells again, so you know.

Hoping someone can help, thanks!

def Logger():

    fileName = myDict[Sub]

    with open(fileName, 'a ', newline="") as file:
        writer = csv.writer(file)

        if file.tell() == 0:
            writer.writerow(["Date", "Asset", "Fear", "Anger", "Anticipation", "Trust", "Surprise", "Sadness", "Disgust", "Joy",
                        "Positivity", "Negativity"])
        writer.writerow([date, Sub, fear, anger, anticip, trust, surprise, sadness, disgust, joy, positivity, negativity])

enter image description here

CodePudding user response：

Try this instead...

    def Logger(col_one, col_two):
        fileName = 'data.csv'

        with open(fileName, 'a ') as file:
            writer = csv.writer(file)
            file.seek(0)
            if file.read().strip() == '':
                writer.writerow(["Date", "Asset"])
            writer.writerow([col_one, col_two])

CodePudding user response：

At first I thought it was a simple matter of there not being a trailing newline, and the new row being appended on the same line, right after the last row, but I can see what looks like a row's worth of empty columns between them.

This whole appending thing looks tricky. If you don't have to use Python, and can use a command-line tool instead, I recommend GoCSV.

Here's a sample file based on your screenshot I mocked up:

base.csv

Date,Asset,Fear,Anger,Anticipation,Trust,Surprise,Sadness,Disgust,Joy,Positivity,Negativity
Nov 1,5088,0.84,0.58,0.73,1.0,0.26,0.89,0.22,0.5,0.69,0.59
Nov 2,4580,0.0,0.88,0.7,0.71,0.57,0.78,0.2,0.22,0.21,0.17
Nov 3,2469,0.72,0.4,0.66,0.53,0.65,0.64,0.67,0.78,0.54,0.32,,,,,,,

I'm calling it base because it's the file that will be growing, and you can see it's got a problem on the last line: all those extras commas (I don't know how they got there