CODEWITHSUNDEEP
pythonpandasdataframe
sariii
sariii

Reputation: 2150

how can I add different size of the values into a pandas data frame at a time

I need to fill a data frame gradually. in each step, I have a data like this:

pubid = 1
keywords = [2, 2,3]

knowing that the length of values for the column are not equal how can I form a data frame like this:

pubid   keyword
1         2
1         2
1         3

So next time when the new data is coming and is like this:

pubid = 6
keywords = [10, 11]

my data frame becomes:

pubid   keyword
1         2
1         2
1         3
6         10
6         11

I tried to create a temp dataframe at the beginning and add the values like this:

data = {'pubid': 1, 'keywords':[1]}
df = pd.DataFrame(data)
pubid = 3
keyword = [2, 3]
df['pubid'] = 3
df["keywords"] = df["pubid"].apply(lambda x: i for i in keyword)

It does not work in this way, but don't know how can I solve it.

Upvotes: 1

Views: 31

Answers (2)

Tarik
Tarik

Reputation: 11209

Create a new DataFrame first:

pubid = 6
keywords = [10, 11]
dr = pd.DataFrame({'pubid' : ['pubid' for _ in keywords], 'keyword': keywords]})

Then append it to the original DataFrame.

Depending on the amount of data you have, you may or may not experience slugish performance.

Upvotes: 1

Andrej Kesely
Andrej Kesely

Reputation: 195528

pubid = 1
keywords = [2, 2,3]

df = pd.DataFrame({'pubid': pubid, 'keywords': keywords})
print(df)

Prints:

   pubid  keywords
0      1         2
1      1         2
2      1         3

Then you can use pd.concat to add data to existing DataFrame:

pubid = 6
keywords = [10, 11]

df = pd.concat([df, pd.DataFrame({'pubid': pubid, 'keywords': keywords})]).reset_index(drop=True)
print(df)

Prints:

   pubid  keywords
0      1         2
1      1         2
2      1         3
3      6        10
4      6        11

Upvotes: 1

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