Is there a way to drop duplicated rows based on an unhashable column?how to impute missing values on numpy...

Does the "particle exchange" operator have any validity?

Trouble with Impersonal Passive Voice usage

Unwarranted claim of higher degree of accuracy in zircon geochronology

Is there a better way to make this?

Why did Jodrell Bank assist the Soviet Union to collect data from their spacecraft in the mid 1960's?

Why did the villain in the first Men in Black movie care about Earth's Cockroaches?

Closed form for these polynomials?

Using only 1s, make 29 with the minimum number of digits

A starship is travelling at 0.9c and collides with a small rock. Will it leave a clean hole through, or will more happen?

The vanishing of sum of coefficients: symmetric polynomials

How should I handle players who ignore the session zero agreement?

Eww, those bytes are gross

How to deal with an incendiary email that was recalled

Number of FLOP (Floating Point Operations) for exponentiation

Program that converts a number to a letter of the alphabet

Does Windows 10's telemetry include sending *.doc files if Word crashed?

Am I a Rude Number?

Can pricing be copyrighted?

Can a person refuse a presidential pardon?

How can I improve my fireworks photography?

Do authors have to be politically correct in article-writing?

Tikzing a circled star

It took me a lot of time to make this, pls like. (YouTube Comments #1)

Strange Sign on Lab Door



Is there a way to drop duplicated rows based on an unhashable column?


how to impute missing values on numpy array created by train_test_split from pandas.DataFrame?How do I convert a pandas dataframe to a 1d array?How to change a cell in Pandas dataframe with respective frequency of the cell in respective columnPopulate column based on previous row with a twistCounting the occurrence of each string in a pandas dataframe columnCreate new data frames from existing data frame based on unique column valuesHow to statistically prove that a column in a dataframe is not neededShould I use pandas get_dummies and create additional columns or use my own encoding code that keeps 1 column?How can I merge 2+ DataFrame objects without duplicating column names?operations on multiple entries in one column based on conditions meet from multiple column entries













1












$begingroup$


i have a pandas dataframe df with one column z filled with set values



i want to drop duplicated rows where 2 rows are considered duplicated version of one another when they have same column z values ( which are sets ).



import pandas as pd

lnks = [ ( 'a' , 'b' , { 'a' , 'b' } ) , ( 'b' , 'c' , { 'b' , 'c' } ) , ( 'b' , 'a' , { 'a' , 'b' } ) ]
lbls = [ 'x' , 'y' , 'z' ]
df = pd.DataFrame.from_records( lnks , columns = lbls )


Trying to drop duplicated rows based on column z values :



df.drop_duplicates( subset = 'z' , keep='first')


And i get the error message :



TypeError: unhashable type: 'set'


Is there a way to drop duplicated rows based on a unhashable typed column ?










share|improve this question











$endgroup$












  • $begingroup$
    I assume it is a typo - but there isn't actually a duplicate in row z anyway because one b also has a space: 'b '.
    $endgroup$
    – n1k31t4
    4 hours ago










  • $begingroup$
    right. I've made a correction. thx.
    $endgroup$
    – Fabrice BOUCHAREL
    3 hours ago
















1












$begingroup$


i have a pandas dataframe df with one column z filled with set values



i want to drop duplicated rows where 2 rows are considered duplicated version of one another when they have same column z values ( which are sets ).



import pandas as pd

lnks = [ ( 'a' , 'b' , { 'a' , 'b' } ) , ( 'b' , 'c' , { 'b' , 'c' } ) , ( 'b' , 'a' , { 'a' , 'b' } ) ]
lbls = [ 'x' , 'y' , 'z' ]
df = pd.DataFrame.from_records( lnks , columns = lbls )


Trying to drop duplicated rows based on column z values :



df.drop_duplicates( subset = 'z' , keep='first')


And i get the error message :



TypeError: unhashable type: 'set'


Is there a way to drop duplicated rows based on a unhashable typed column ?










share|improve this question











$endgroup$












  • $begingroup$
    I assume it is a typo - but there isn't actually a duplicate in row z anyway because one b also has a space: 'b '.
    $endgroup$
    – n1k31t4
    4 hours ago










  • $begingroup$
    right. I've made a correction. thx.
    $endgroup$
    – Fabrice BOUCHAREL
    3 hours ago














1












1








1





$begingroup$


i have a pandas dataframe df with one column z filled with set values



i want to drop duplicated rows where 2 rows are considered duplicated version of one another when they have same column z values ( which are sets ).



import pandas as pd

lnks = [ ( 'a' , 'b' , { 'a' , 'b' } ) , ( 'b' , 'c' , { 'b' , 'c' } ) , ( 'b' , 'a' , { 'a' , 'b' } ) ]
lbls = [ 'x' , 'y' , 'z' ]
df = pd.DataFrame.from_records( lnks , columns = lbls )


Trying to drop duplicated rows based on column z values :



df.drop_duplicates( subset = 'z' , keep='first')


And i get the error message :



TypeError: unhashable type: 'set'


Is there a way to drop duplicated rows based on a unhashable typed column ?










share|improve this question











$endgroup$




i have a pandas dataframe df with one column z filled with set values



i want to drop duplicated rows where 2 rows are considered duplicated version of one another when they have same column z values ( which are sets ).



import pandas as pd

lnks = [ ( 'a' , 'b' , { 'a' , 'b' } ) , ( 'b' , 'c' , { 'b' , 'c' } ) , ( 'b' , 'a' , { 'a' , 'b' } ) ]
lbls = [ 'x' , 'y' , 'z' ]
df = pd.DataFrame.from_records( lnks , columns = lbls )


Trying to drop duplicated rows based on column z values :



df.drop_duplicates( subset = 'z' , keep='first')


And i get the error message :



TypeError: unhashable type: 'set'


Is there a way to drop duplicated rows based on a unhashable typed column ?







python pandas dataframe






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited 1 hour ago









n1k31t4

6,1362319




6,1362319










asked 5 hours ago









Fabrice BOUCHARELFabrice BOUCHAREL

585




585












  • $begingroup$
    I assume it is a typo - but there isn't actually a duplicate in row z anyway because one b also has a space: 'b '.
    $endgroup$
    – n1k31t4
    4 hours ago










  • $begingroup$
    right. I've made a correction. thx.
    $endgroup$
    – Fabrice BOUCHAREL
    3 hours ago


















  • $begingroup$
    I assume it is a typo - but there isn't actually a duplicate in row z anyway because one b also has a space: 'b '.
    $endgroup$
    – n1k31t4
    4 hours ago










  • $begingroup$
    right. I've made a correction. thx.
    $endgroup$
    – Fabrice BOUCHAREL
    3 hours ago
















$begingroup$
I assume it is a typo - but there isn't actually a duplicate in row z anyway because one b also has a space: 'b '.
$endgroup$
– n1k31t4
4 hours ago




$begingroup$
I assume it is a typo - but there isn't actually a duplicate in row z anyway because one b also has a space: 'b '.
$endgroup$
– n1k31t4
4 hours ago












$begingroup$
right. I've made a correction. thx.
$endgroup$
– Fabrice BOUCHAREL
3 hours ago




$begingroup$
right. I've made a correction. thx.
$endgroup$
– Fabrice BOUCHAREL
3 hours ago










1 Answer
1






active

oldest

votes


















2












$begingroup$

It is true that a set is not hashable (it cannot be used as a key in a hashmap a.k.a a dictionary). So what you can do is to just convert the column to a type that is hashable - I would go for a tuple.



I made a new column that is just the "z" column you had, converted to tuples. Then you can use the same method you tried to, on the new column:



In [1] : import pandas as pd 
...:
...: lnks = [ ( 'a' , 'b' , { 'a' , 'b' } ) , ( 'b' , 'c' , { 'b' , 'c' } )
...: , ( 'b' , 'a' , { 'a' , 'b' } ) ]
...: lbls = [ 'x' , 'y' , 'z' ]
...: df = pd.DataFrame.from_records( lnks , columns = lbls)

In [2]: df["z_tuple"] = df.z.apply(lambda x: tuple(x))

In [3]: df.drop_duplicates(subset="z_tuple", keep="first")
Out[3]:
x y z z_tuple
0 a b {b, a} (b, a)
1 b c {c, b} (c, b)


The apply method lets you apply a function to each item in a column, and then returns the values as a new column (a Pandas Series object). This lets you assign it back to the original DataFrame as a new column, as I did.



You can also remove the "z_tuple" column then if you no longer want it:



In [4] : df.drop("z_tuple", axis=1, inplace=True)                               

In [5] : df
Out[5] :
x y z
0 a b {b, a}
1 b c {c, b}
2 b a {b, a}





share|improve this answer









$endgroup$













    Your Answer





    StackExchange.ifUsing("editor", function () {
    return StackExchange.using("mathjaxEditing", function () {
    StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
    StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
    });
    });
    }, "mathjax-editing");

    StackExchange.ready(function() {
    var channelOptions = {
    tags: "".split(" "),
    id: "557"
    };
    initTagRenderer("".split(" "), "".split(" "), channelOptions);

    StackExchange.using("externalEditor", function() {
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled) {
    StackExchange.using("snippets", function() {
    createEditor();
    });
    }
    else {
    createEditor();
    }
    });

    function createEditor() {
    StackExchange.prepareEditor({
    heartbeatType: 'answer',
    autoActivateHeartbeat: false,
    convertImagesToLinks: false,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: null,
    bindNavPrevention: true,
    postfix: "",
    imageUploader: {
    brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
    contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
    allowUrls: true
    },
    onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    });


    }
    });














    draft saved

    draft discarded


















    StackExchange.ready(
    function () {
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fdatascience.stackexchange.com%2fquestions%2f46541%2fis-there-a-way-to-drop-duplicated-rows-based-on-an-unhashable-column%23new-answer', 'question_page');
    }
    );

    Post as a guest















    Required, but never shown

























    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    2












    $begingroup$

    It is true that a set is not hashable (it cannot be used as a key in a hashmap a.k.a a dictionary). So what you can do is to just convert the column to a type that is hashable - I would go for a tuple.



    I made a new column that is just the "z" column you had, converted to tuples. Then you can use the same method you tried to, on the new column:



    In [1] : import pandas as pd 
    ...:
    ...: lnks = [ ( 'a' , 'b' , { 'a' , 'b' } ) , ( 'b' , 'c' , { 'b' , 'c' } )
    ...: , ( 'b' , 'a' , { 'a' , 'b' } ) ]
    ...: lbls = [ 'x' , 'y' , 'z' ]
    ...: df = pd.DataFrame.from_records( lnks , columns = lbls)

    In [2]: df["z_tuple"] = df.z.apply(lambda x: tuple(x))

    In [3]: df.drop_duplicates(subset="z_tuple", keep="first")
    Out[3]:
    x y z z_tuple
    0 a b {b, a} (b, a)
    1 b c {c, b} (c, b)


    The apply method lets you apply a function to each item in a column, and then returns the values as a new column (a Pandas Series object). This lets you assign it back to the original DataFrame as a new column, as I did.



    You can also remove the "z_tuple" column then if you no longer want it:



    In [4] : df.drop("z_tuple", axis=1, inplace=True)                               

    In [5] : df
    Out[5] :
    x y z
    0 a b {b, a}
    1 b c {c, b}
    2 b a {b, a}





    share|improve this answer









    $endgroup$


















      2












      $begingroup$

      It is true that a set is not hashable (it cannot be used as a key in a hashmap a.k.a a dictionary). So what you can do is to just convert the column to a type that is hashable - I would go for a tuple.



      I made a new column that is just the "z" column you had, converted to tuples. Then you can use the same method you tried to, on the new column:



      In [1] : import pandas as pd 
      ...:
      ...: lnks = [ ( 'a' , 'b' , { 'a' , 'b' } ) , ( 'b' , 'c' , { 'b' , 'c' } )
      ...: , ( 'b' , 'a' , { 'a' , 'b' } ) ]
      ...: lbls = [ 'x' , 'y' , 'z' ]
      ...: df = pd.DataFrame.from_records( lnks , columns = lbls)

      In [2]: df["z_tuple"] = df.z.apply(lambda x: tuple(x))

      In [3]: df.drop_duplicates(subset="z_tuple", keep="first")
      Out[3]:
      x y z z_tuple
      0 a b {b, a} (b, a)
      1 b c {c, b} (c, b)


      The apply method lets you apply a function to each item in a column, and then returns the values as a new column (a Pandas Series object). This lets you assign it back to the original DataFrame as a new column, as I did.



      You can also remove the "z_tuple" column then if you no longer want it:



      In [4] : df.drop("z_tuple", axis=1, inplace=True)                               

      In [5] : df
      Out[5] :
      x y z
      0 a b {b, a}
      1 b c {c, b}
      2 b a {b, a}





      share|improve this answer









      $endgroup$
















        2












        2








        2





        $begingroup$

        It is true that a set is not hashable (it cannot be used as a key in a hashmap a.k.a a dictionary). So what you can do is to just convert the column to a type that is hashable - I would go for a tuple.



        I made a new column that is just the "z" column you had, converted to tuples. Then you can use the same method you tried to, on the new column:



        In [1] : import pandas as pd 
        ...:
        ...: lnks = [ ( 'a' , 'b' , { 'a' , 'b' } ) , ( 'b' , 'c' , { 'b' , 'c' } )
        ...: , ( 'b' , 'a' , { 'a' , 'b' } ) ]
        ...: lbls = [ 'x' , 'y' , 'z' ]
        ...: df = pd.DataFrame.from_records( lnks , columns = lbls)

        In [2]: df["z_tuple"] = df.z.apply(lambda x: tuple(x))

        In [3]: df.drop_duplicates(subset="z_tuple", keep="first")
        Out[3]:
        x y z z_tuple
        0 a b {b, a} (b, a)
        1 b c {c, b} (c, b)


        The apply method lets you apply a function to each item in a column, and then returns the values as a new column (a Pandas Series object). This lets you assign it back to the original DataFrame as a new column, as I did.



        You can also remove the "z_tuple" column then if you no longer want it:



        In [4] : df.drop("z_tuple", axis=1, inplace=True)                               

        In [5] : df
        Out[5] :
        x y z
        0 a b {b, a}
        1 b c {c, b}
        2 b a {b, a}





        share|improve this answer









        $endgroup$



        It is true that a set is not hashable (it cannot be used as a key in a hashmap a.k.a a dictionary). So what you can do is to just convert the column to a type that is hashable - I would go for a tuple.



        I made a new column that is just the "z" column you had, converted to tuples. Then you can use the same method you tried to, on the new column:



        In [1] : import pandas as pd 
        ...:
        ...: lnks = [ ( 'a' , 'b' , { 'a' , 'b' } ) , ( 'b' , 'c' , { 'b' , 'c' } )
        ...: , ( 'b' , 'a' , { 'a' , 'b' } ) ]
        ...: lbls = [ 'x' , 'y' , 'z' ]
        ...: df = pd.DataFrame.from_records( lnks , columns = lbls)

        In [2]: df["z_tuple"] = df.z.apply(lambda x: tuple(x))

        In [3]: df.drop_duplicates(subset="z_tuple", keep="first")
        Out[3]:
        x y z z_tuple
        0 a b {b, a} (b, a)
        1 b c {c, b} (c, b)


        The apply method lets you apply a function to each item in a column, and then returns the values as a new column (a Pandas Series object). This lets you assign it back to the original DataFrame as a new column, as I did.



        You can also remove the "z_tuple" column then if you no longer want it:



        In [4] : df.drop("z_tuple", axis=1, inplace=True)                               

        In [5] : df
        Out[5] :
        x y z
        0 a b {b, a}
        1 b c {c, b}
        2 b a {b, a}






        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered 4 hours ago









        n1k31t4n1k31t4

        6,1362319




        6,1362319






























            draft saved

            draft discarded




















































            Thanks for contributing an answer to Data Science Stack Exchange!


            • Please be sure to answer the question. Provide details and share your research!

            But avoid



            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.


            Use MathJax to format equations. MathJax reference.


            To learn more, see our tips on writing great answers.




            draft saved


            draft discarded














            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fdatascience.stackexchange.com%2fquestions%2f46541%2fis-there-a-way-to-drop-duplicated-rows-based-on-an-unhashable-column%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown





















































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown

































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown







            Popular posts from this blog

            VNC viewer RFB protocol error: bad desktop size 0x0I Cannot Type the Key 'd' (lowercase) in VNC Viewer...

            Tribunal Administrativo e Fiscal de Mirandela Referências Menu de...

            looking for continuous Screen Capture for retroactivly reproducing errors, timeback machineRolling desktop...