Pandas Dataframes operation









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I use pandas dataframes to process my dataset. I have 3 columns, airport_id airline_id and delay. I want to remove all origin airports that have less than 5 airlines.



I did this:



grouped_size = df.groupby(['OP_CARRIER_AIRLINE_ID','ORIGIN_AIRPORT_ID']).size()


Which gives me the number of airlines per airport(I hope) but I do not know how to remove the ones with less than 5 airlines. Thank you!










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  • df = df[df.groupby(['OP_CARRIER_AIRLINE_ID','ORIGIN_AIRPORT_ID']).transform('count') >= 5]?
    – coldspeed
    Nov 12 at 0:55











  • @coldspeed or use groupby(...).filter(...) - save materialising a Series if it's not being used for anything?
    – Jon Clements
    Nov 12 at 0:59











  • @JonClements, I'm guessing filter would require lambda? If so, I'm all in favour of avoiding lamda :).
    – jpp
    Nov 12 at 0:59











  • @coldspeed I get this error "ValueError: Boolean array expected for the condition, not float64"
    – Kaan Yolsever
    Nov 12 at 1:03











  • @KaanYolsever Please copy the entire command properly.
    – coldspeed
    Nov 12 at 1:22














up vote
-1
down vote

favorite












I use pandas dataframes to process my dataset. I have 3 columns, airport_id airline_id and delay. I want to remove all origin airports that have less than 5 airlines.



I did this:



grouped_size = df.groupby(['OP_CARRIER_AIRLINE_ID','ORIGIN_AIRPORT_ID']).size()


Which gives me the number of airlines per airport(I hope) but I do not know how to remove the ones with less than 5 airlines. Thank you!










share|improve this question























  • df = df[df.groupby(['OP_CARRIER_AIRLINE_ID','ORIGIN_AIRPORT_ID']).transform('count') >= 5]?
    – coldspeed
    Nov 12 at 0:55











  • @coldspeed or use groupby(...).filter(...) - save materialising a Series if it's not being used for anything?
    – Jon Clements
    Nov 12 at 0:59











  • @JonClements, I'm guessing filter would require lambda? If so, I'm all in favour of avoiding lamda :).
    – jpp
    Nov 12 at 0:59











  • @coldspeed I get this error "ValueError: Boolean array expected for the condition, not float64"
    – Kaan Yolsever
    Nov 12 at 1:03











  • @KaanYolsever Please copy the entire command properly.
    – coldspeed
    Nov 12 at 1:22












up vote
-1
down vote

favorite









up vote
-1
down vote

favorite











I use pandas dataframes to process my dataset. I have 3 columns, airport_id airline_id and delay. I want to remove all origin airports that have less than 5 airlines.



I did this:



grouped_size = df.groupby(['OP_CARRIER_AIRLINE_ID','ORIGIN_AIRPORT_ID']).size()


Which gives me the number of airlines per airport(I hope) but I do not know how to remove the ones with less than 5 airlines. Thank you!










share|improve this question















I use pandas dataframes to process my dataset. I have 3 columns, airport_id airline_id and delay. I want to remove all origin airports that have less than 5 airlines.



I did this:



grouped_size = df.groupby(['OP_CARRIER_AIRLINE_ID','ORIGIN_AIRPORT_ID']).size()


Which gives me the number of airlines per airport(I hope) but I do not know how to remove the ones with less than 5 airlines. Thank you!







python pandas pandas-groupby






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Nov 12 at 0:55









Jon Clements

97.9k19173218




97.9k19173218










asked Nov 12 at 0:53









Kaan Yolsever

12




12











  • df = df[df.groupby(['OP_CARRIER_AIRLINE_ID','ORIGIN_AIRPORT_ID']).transform('count') >= 5]?
    – coldspeed
    Nov 12 at 0:55











  • @coldspeed or use groupby(...).filter(...) - save materialising a Series if it's not being used for anything?
    – Jon Clements
    Nov 12 at 0:59











  • @JonClements, I'm guessing filter would require lambda? If so, I'm all in favour of avoiding lamda :).
    – jpp
    Nov 12 at 0:59











  • @coldspeed I get this error "ValueError: Boolean array expected for the condition, not float64"
    – Kaan Yolsever
    Nov 12 at 1:03











  • @KaanYolsever Please copy the entire command properly.
    – coldspeed
    Nov 12 at 1:22
















  • df = df[df.groupby(['OP_CARRIER_AIRLINE_ID','ORIGIN_AIRPORT_ID']).transform('count') >= 5]?
    – coldspeed
    Nov 12 at 0:55











  • @coldspeed or use groupby(...).filter(...) - save materialising a Series if it's not being used for anything?
    – Jon Clements
    Nov 12 at 0:59











  • @JonClements, I'm guessing filter would require lambda? If so, I'm all in favour of avoiding lamda :).
    – jpp
    Nov 12 at 0:59











  • @coldspeed I get this error "ValueError: Boolean array expected for the condition, not float64"
    – Kaan Yolsever
    Nov 12 at 1:03











  • @KaanYolsever Please copy the entire command properly.
    – coldspeed
    Nov 12 at 1:22















df = df[df.groupby(['OP_CARRIER_AIRLINE_ID','ORIGIN_AIRPORT_ID']).transform('count') >= 5]?
– coldspeed
Nov 12 at 0:55





df = df[df.groupby(['OP_CARRIER_AIRLINE_ID','ORIGIN_AIRPORT_ID']).transform('count') >= 5]?
– coldspeed
Nov 12 at 0:55













@coldspeed or use groupby(...).filter(...) - save materialising a Series if it's not being used for anything?
– Jon Clements
Nov 12 at 0:59





@coldspeed or use groupby(...).filter(...) - save materialising a Series if it's not being used for anything?
– Jon Clements
Nov 12 at 0:59













@JonClements, I'm guessing filter would require lambda? If so, I'm all in favour of avoiding lamda :).
– jpp
Nov 12 at 0:59





@JonClements, I'm guessing filter would require lambda? If so, I'm all in favour of avoiding lamda :).
– jpp
Nov 12 at 0:59













@coldspeed I get this error "ValueError: Boolean array expected for the condition, not float64"
– Kaan Yolsever
Nov 12 at 1:03





@coldspeed I get this error "ValueError: Boolean array expected for the condition, not float64"
– Kaan Yolsever
Nov 12 at 1:03













@KaanYolsever Please copy the entire command properly.
– coldspeed
Nov 12 at 1:22




@KaanYolsever Please copy the entire command properly.
– coldspeed
Nov 12 at 1:22












1 Answer
1






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oldest

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up vote
0
down vote













Here is a simple way to do it:



grouped_size = df.groupby(['OP_CARRIER_AIRLINE_ID','ORIGIN_AIRPORT_ID']).size().reset_index()
grouped_size.columns = ['OP_CARRIER_AIRLINE_ID','ORIGIN_AIRPORT_ID', 'size']
hi_mask = grouped_size['size'] > 5
grouped_size = grouped_size[hi_mask]





share|improve this answer






















  • @ thank you but i get this error: '>' not supported between instances of 'str' and 'int'
    – Kaan Yolsever
    Nov 12 at 1:20











  • corrected the code, please try it
    – jeevs
    Nov 12 at 1:33










  • one thing is when I do this I lose my other columns. How can I do this while preserving them in the output data structure?
    – Kaan Yolsever
    Nov 12 at 1:39










  • Once you do a groupby, you are basically asking pandas to count on the base dataframe. Hence, you no more are working with the base dataframe. If you want to pick only the those that satisfy this criteria, you will need to merge the groupy df with the base df, and filter again.
    – jeevs
    Nov 12 at 1:46










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1 Answer
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1 Answer
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active

oldest

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up vote
0
down vote













Here is a simple way to do it:



grouped_size = df.groupby(['OP_CARRIER_AIRLINE_ID','ORIGIN_AIRPORT_ID']).size().reset_index()
grouped_size.columns = ['OP_CARRIER_AIRLINE_ID','ORIGIN_AIRPORT_ID', 'size']
hi_mask = grouped_size['size'] > 5
grouped_size = grouped_size[hi_mask]





share|improve this answer






















  • @ thank you but i get this error: '>' not supported between instances of 'str' and 'int'
    – Kaan Yolsever
    Nov 12 at 1:20











  • corrected the code, please try it
    – jeevs
    Nov 12 at 1:33










  • one thing is when I do this I lose my other columns. How can I do this while preserving them in the output data structure?
    – Kaan Yolsever
    Nov 12 at 1:39










  • Once you do a groupby, you are basically asking pandas to count on the base dataframe. Hence, you no more are working with the base dataframe. If you want to pick only the those that satisfy this criteria, you will need to merge the groupy df with the base df, and filter again.
    – jeevs
    Nov 12 at 1:46














up vote
0
down vote













Here is a simple way to do it:



grouped_size = df.groupby(['OP_CARRIER_AIRLINE_ID','ORIGIN_AIRPORT_ID']).size().reset_index()
grouped_size.columns = ['OP_CARRIER_AIRLINE_ID','ORIGIN_AIRPORT_ID', 'size']
hi_mask = grouped_size['size'] > 5
grouped_size = grouped_size[hi_mask]





share|improve this answer






















  • @ thank you but i get this error: '>' not supported between instances of 'str' and 'int'
    – Kaan Yolsever
    Nov 12 at 1:20











  • corrected the code, please try it
    – jeevs
    Nov 12 at 1:33










  • one thing is when I do this I lose my other columns. How can I do this while preserving them in the output data structure?
    – Kaan Yolsever
    Nov 12 at 1:39










  • Once you do a groupby, you are basically asking pandas to count on the base dataframe. Hence, you no more are working with the base dataframe. If you want to pick only the those that satisfy this criteria, you will need to merge the groupy df with the base df, and filter again.
    – jeevs
    Nov 12 at 1:46












up vote
0
down vote










up vote
0
down vote









Here is a simple way to do it:



grouped_size = df.groupby(['OP_CARRIER_AIRLINE_ID','ORIGIN_AIRPORT_ID']).size().reset_index()
grouped_size.columns = ['OP_CARRIER_AIRLINE_ID','ORIGIN_AIRPORT_ID', 'size']
hi_mask = grouped_size['size'] > 5
grouped_size = grouped_size[hi_mask]





share|improve this answer














Here is a simple way to do it:



grouped_size = df.groupby(['OP_CARRIER_AIRLINE_ID','ORIGIN_AIRPORT_ID']).size().reset_index()
grouped_size.columns = ['OP_CARRIER_AIRLINE_ID','ORIGIN_AIRPORT_ID', 'size']
hi_mask = grouped_size['size'] > 5
grouped_size = grouped_size[hi_mask]






share|improve this answer














share|improve this answer



share|improve this answer








edited Nov 12 at 1:33

























answered Nov 12 at 1:12









jeevs

1164




1164











  • @ thank you but i get this error: '>' not supported between instances of 'str' and 'int'
    – Kaan Yolsever
    Nov 12 at 1:20











  • corrected the code, please try it
    – jeevs
    Nov 12 at 1:33










  • one thing is when I do this I lose my other columns. How can I do this while preserving them in the output data structure?
    – Kaan Yolsever
    Nov 12 at 1:39










  • Once you do a groupby, you are basically asking pandas to count on the base dataframe. Hence, you no more are working with the base dataframe. If you want to pick only the those that satisfy this criteria, you will need to merge the groupy df with the base df, and filter again.
    – jeevs
    Nov 12 at 1:46
















  • @ thank you but i get this error: '>' not supported between instances of 'str' and 'int'
    – Kaan Yolsever
    Nov 12 at 1:20











  • corrected the code, please try it
    – jeevs
    Nov 12 at 1:33










  • one thing is when I do this I lose my other columns. How can I do this while preserving them in the output data structure?
    – Kaan Yolsever
    Nov 12 at 1:39










  • Once you do a groupby, you are basically asking pandas to count on the base dataframe. Hence, you no more are working with the base dataframe. If you want to pick only the those that satisfy this criteria, you will need to merge the groupy df with the base df, and filter again.
    – jeevs
    Nov 12 at 1:46















@ thank you but i get this error: '>' not supported between instances of 'str' and 'int'
– Kaan Yolsever
Nov 12 at 1:20





@ thank you but i get this error: '>' not supported between instances of 'str' and 'int'
– Kaan Yolsever
Nov 12 at 1:20













corrected the code, please try it
– jeevs
Nov 12 at 1:33




corrected the code, please try it
– jeevs
Nov 12 at 1:33












one thing is when I do this I lose my other columns. How can I do this while preserving them in the output data structure?
– Kaan Yolsever
Nov 12 at 1:39




one thing is when I do this I lose my other columns. How can I do this while preserving them in the output data structure?
– Kaan Yolsever
Nov 12 at 1:39












Once you do a groupby, you are basically asking pandas to count on the base dataframe. Hence, you no more are working with the base dataframe. If you want to pick only the those that satisfy this criteria, you will need to merge the groupy df with the base df, and filter again.
– jeevs
Nov 12 at 1:46




Once you do a groupby, you are basically asking pandas to count on the base dataframe. Hence, you no more are working with the base dataframe. If you want to pick only the those that satisfy this criteria, you will need to merge the groupy df with the base df, and filter again.
– jeevs
Nov 12 at 1:46

















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