How to write a dataframe/list into a csv-file?

Question

I have written the following code and I want to write the output into a csv file. How can I do this? Thanks for helping me. Here is an extract from my code:

columnNames = ['Stride Length', 'Stand Duration', 'Swing Duration', 'Douple Support Time', 'Relation Swing Stand']

resultsPerRowRatio = list()

for i in range(len(stepData)):
     stepDataLeft = stepData.to_numpy()[i, 0:5]
     stepDataRight = stepData.to_numpy()[i, 5:10]
     dataF = pd.DataFrame({'stepDataLeft': stepDataLeft, 'stepDataRight': stepDataRight}, index=columnNames)

     #Symmetry Ratio:
     dataF['Symmetry Ratio Row']=np.where(dataF['stepDataLeft'] < dataF['stepDataRight'],sv.symmetryRatio(dataF['stepDataLeft'],dataF['stepDataRight']), sv.symmetryRatio(dataF['stepDataRight'],dataF['stepDataLeft']))
     resultsPerRowRatio.append(dataF)

print("Symmetry Ratio: "+str(resultsPerRowRatio))

This is my output:

I want to write this in a csv file. But I don't know how. I have already tried various options.

What is the issue, exactly? Why not ask about the failed attempts at a solution? Stack Overflow is not a free code writing service, right? See: tour, How to Ask, help center, meta.stackoverflow.com/questions/261592/…. — AMC
– AMC, Commented Feb 18, 2020 at 3:49

Andrew · Accepted Answer · 2020-02-18 00:34:46Z

2

This is an approach to consider using to_csv():

to_csv() Parameters(more are available, but this is simple case):

header: column header, True to include or False to exclude
mode: 'a' to append to an existing file, 'w' for creating and writing a new file
index: True to include indexing, False to exclude

Example:

PATH = your_folder_path
FILENAME = output_file_name

if os.path.isfile(PATH+FILENAME):
    dataF.to_csv(PATH+FILENAME, header=False, mode='a', index=True)
else:
    dataF.to_csv(PATH+FILENAME, header=True, mode='w', index=True)

This structure will do a logic check to see if your output file already exists in the folder path you've defined, if it does exist, it will append the data to the csv file without the associated header column names via the to_csv() call. If it doesn't exist, it will generate a new csv file and include the column names as a header.

edited Feb 18, 2020 at 0:34

answered Feb 17, 2020 at 23:22

Andrew

1511 silver badge5 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Sunghee Yun Over a year ago

Any other alternative method?

Collectives™ on Stack Overflow

How to write a dataframe/list into a csv-file?

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related