empty df after using isin function-CodePudding

hello I'm trying to filter out df column that are contained in another dict

here is the sample:

import random
df = pd.DataFrame({'type': random.choice(['222', '44']), #let size be 10k for example
                   'method': random.choice(['open', 'close'])}) 
filter_dict = {'type': {0: ['44']}, 'method': {0: ['open', 'closed']}}

it works fine with df[df['method'].isin(filter_dict['method'][0])]

when i am trying to filter next column like this, i got an empty dataframe

df[df['type'].isin(filter_dict['type'][0])]

idk why it is happening, ty for ur answers

pandas version is 0.23.4

CodePudding user response：

You example is invalid (you have a unique value with random.choice, thus the pandas error), but else, the code is working as expected:

import numpy as np
np.random.seed(0)
df = pd.DataFrame({'type': np.random.choice(['222', '44'], size=20),
                   'method': np.random.choice(['open', 'close'], size=20)})
filter_dict = {'type': {0: ['44']}, 'method': {0: ['open', 'closed']}}

df[df['type'].isin(filter_dict['type'][0])]

output:

   type method
1    44  close
2    44  close
4    44   open
5    44  close
6    44  close
7    44  close
8    44  close
9    44   open
10   44  close
13   44   open
19   44   open

If you want to test the condition on all columns:

mask = np.all([df[c].isin(filter_dict[c][0]) for c in df.columns], axis=0)
df[mask]

output:

   type method
4    44   open
9    44   open
13   44   open
19   44   open