CODEWITHSUNDEEP
python-3.xpandas
Lisa Siurina
Lisa Siurina

Reputation: 33

ValueError: cannot convert float NaN to integer

I am writing a function that returns a dictionary with the year of the docs as key and, as value, it specifies a tuple that is returned by def do_get_citations_per_year function.

This function processes the df:

def do_process_citation_data(f_path):
    global my_ocan

    my_ocan = pd.read_csv(f_path, names=['oci', 'citing', 'cited', 'creation', 'timespan', 'journal_sc', 'author_sc'],
                          parse_dates=['creation', 'timespan'])
    my_ocan = my_ocan.iloc[1:]  # to remove the first row
    my_ocan['creation'] = pd.to_datetime(my_ocan['creation'], format="%Y-%m-%d", yearfirst=True)
    my_ocan['timespan'] = my_ocan['timespan'].map(parse_timespan)
    #print(my_ocan.info())
    print(my_ocan['timespan'])
    return my_ocan

Then I have this function, when running it it does not trigger any error:

    result = tuple()
    my_ocan['creation'] = pd.DatetimeIndex(my_ocan['creation']).year

    len_citations = len(my_ocan.loc[my_ocan["creation"] == year, "creation"])
    timespan = round(my_ocan.loc[my_ocan["creation"] == year, "timespan"].mean())
    result = (len_citations, timespan)
    print(result)


    return result

When I run that function inside of another function:

def do_get_citations_all_years(data):
    mydict = {}
    s = set(my_ocan.creation)
    for year in s:
        mydict[year] = do_get_citations_per_year(data, year)

    return mydict

I get the error:

  File "/Users/lisa/Desktop/yopy/execution_example.py", line 28, in <module>
    print(my_ocan.get_citations_all_years())
  File "/Users/lisa/Desktop/yopy/ocan.py", line 35, in get_citations_all_years
    return do_get_citations_all_years(self.data)
  File "/Users/lisa/Desktop/yopy/lisa.py", line 112, in do_get_citations_all_years
    mydict[year] = do_get_citations_per_year(data, year)
  File "/Users/lisa/Desktop/yopy/lisa.py", line 99, in do_get_citations_per_year
    timespan = round(my_ocan.loc[my_ocan["creation"] == year, "timespan"].mean())
ValueError: cannot convert float NaN to integer

What can I do to solve the issue?

Thank you in advance

Upvotes: 0

Views: 1264

Answers (2)

Luis Blanche
Luis Blanche

Reputation: 627

@Ha Bom, filling with zeros will change the mean, I guess the solution would be to drop rows with NaN instead : 

timespan = my_ocan.loc[my_ocan["creation"] == year, "timespan"].dropna().mean()

If you do not want to drop any rows than you will want to fillna with mean for example see this Stackoverflow question for an example

Edit @Ha Bom solution was good seing that the point was to replace the mean by zero

Upvotes: 0

Ha Bom
Ha Bom

Reputation: 2917

This error means that my_ocan.loc[my_ocan["creation"] == year, "timespan"].mean() is NaN.

You should fill NaN values with 0 before calculating mean because it will not change the mean. Here is an example:

timespan = my_ocan.loc[my_ocan["creation"] == year, "timespan"].fillna(0).mean()

Upvotes: 1

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