Trouble passing in lambda to apply for pandas DataFrame
Note there is no axis
param for a Series.apply
call, as distinct to a DataFrame.apply
call.
Series.apply(func, convert_dtype=True, args=(), **kwds)
func : function
convert_dtype : boolean, default True
Try to find better dtype for elementwise function results. If False, leave as dtype=object
args : tuple
Positional arguments to pass to function in addition to the value
There is one for a df but it's unclear how you're expecting this to work when you're calling it on a series but you're expecting it to work on a row?
sedavidw
Updated on July 05, 2022Comments
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sedavidw almost 2 years
I'm trying to apply a function to all rows of a pandas DataFrame (actually just one column in that DataFrame)
I'm sure this is a syntax error but I'm know sure what I'm doing wrong
df['col'].apply(lambda x, y:(x - y).total_seconds(), args=[d1], axis=1)
The
col
column contains a bunch adatetime.datetime
objects and andd1
is the earliest of them. I'm trying to get a column of the total number of seconds for each of the rowsEDIT I keep getting the following error
TypeError: <lambda>() got an unexpected keyword argument 'axis'
I don't understand why
axis
is getting passed to mylambda
functionEDIT 2
I've also tried doing
def diff_dates(d1, d2): return (d1-d2).total_seconds() df['col'].apply(diff_dates, args=[d1], axis=1)
And I get the same error