python - Memory error when using Pandas built-in divide, but looping works? -


i have 2 dataframes, each having 100,000 rows. trying following:

new = dataframea['mykey']/dataframeb['mykey']

and 'out of memory' error. same error if try:

new = dataframea['mykey'].divide(dataframeb['mykey'])

but if loop through each element, this, works:

result = [] idx in range(0,dataframea.shape[0]):     result.append(dataframea.ix[idx,'mykey']/dataframeb.ix[idx,'mykey'])

what's going on here? i'd think built-in pandas functions more memory efficient.

@ayhan got right off bat.

my 2 dataframes not using same indices. resetting them worked.


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