Splitting pandas dataframe column (into two) after the first letter in the cell











up vote
3
down vote

favorite












The problem



I would like to split a column from a pandas dataframe into 2 columns, in the percentage column (see below), each entry starts with a capitalised alphabet character, I would like to split the 'Percentage' column immediately after this letter, with the new column labelled 'Amino Acid'.



Current Code:



import pandas as pd

df = pd.read_csv('foo.csv')

df['Amino Acid'], df['Percentage'] = zip(*df['Percentage'].map(lambda x: x.split('[^a-zA-Z]')))

df.to_csv('bar.csv',index=False)


Example of input data



+-----------------------------+-------+-----+-----------+---------------------------------------------------------------------------------------------+
| Species | ID | OGT | DB | Percentage |
+-----------------------------+-------+-----+-----------+---------------------------------------------------------------------------------------------+
| Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | E is 8.333003365670164% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
| Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | R is 6.310991522830762% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
| Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | A is 10.22668778459711% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
+-----------------------------+-------+-----+-----------+---------------------------------------------------------------------------------------------+


Example of desired output



+-----------------------------+-------+-----+-----------+------------+--------------------------------------------------------------------------------------------+
| Species | ID | OGT | DB | Amino Acid | Percentage |
+-----------------------------+-------+-----+-----------+------------+--------------------------------------------------------------------------------------------+
| Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | E | is 8.333003365670164% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
| Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | R | is 6.310991522830762% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
| Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | A | is 10.22668778459711% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
+-----------------------------+-------+-----+-----------+------------+--------------------------------------------------------------------------------------------+









share|improve this question




























    up vote
    3
    down vote

    favorite












    The problem



    I would like to split a column from a pandas dataframe into 2 columns, in the percentage column (see below), each entry starts with a capitalised alphabet character, I would like to split the 'Percentage' column immediately after this letter, with the new column labelled 'Amino Acid'.



    Current Code:



    import pandas as pd

    df = pd.read_csv('foo.csv')

    df['Amino Acid'], df['Percentage'] = zip(*df['Percentage'].map(lambda x: x.split('[^a-zA-Z]')))

    df.to_csv('bar.csv',index=False)


    Example of input data



    +-----------------------------+-------+-----+-----------+---------------------------------------------------------------------------------------------+
    | Species | ID | OGT | DB | Percentage |
    +-----------------------------+-------+-----+-----------+---------------------------------------------------------------------------------------------+
    | Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | E is 8.333003365670164% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
    | Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | R is 6.310991522830762% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
    | Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | A is 10.22668778459711% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
    +-----------------------------+-------+-----+-----------+---------------------------------------------------------------------------------------------+


    Example of desired output



    +-----------------------------+-------+-----+-----------+------------+--------------------------------------------------------------------------------------------+
    | Species | ID | OGT | DB | Amino Acid | Percentage |
    +-----------------------------+-------+-----+-----------+------------+--------------------------------------------------------------------------------------------+
    | Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | E | is 8.333003365670164% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
    | Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | R | is 6.310991522830762% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
    | Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | A | is 10.22668778459711% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
    +-----------------------------+-------+-----+-----------+------------+--------------------------------------------------------------------------------------------+









    share|improve this question


























      up vote
      3
      down vote

      favorite









      up vote
      3
      down vote

      favorite











      The problem



      I would like to split a column from a pandas dataframe into 2 columns, in the percentage column (see below), each entry starts with a capitalised alphabet character, I would like to split the 'Percentage' column immediately after this letter, with the new column labelled 'Amino Acid'.



      Current Code:



      import pandas as pd

      df = pd.read_csv('foo.csv')

      df['Amino Acid'], df['Percentage'] = zip(*df['Percentage'].map(lambda x: x.split('[^a-zA-Z]')))

      df.to_csv('bar.csv',index=False)


      Example of input data



      +-----------------------------+-------+-----+-----------+---------------------------------------------------------------------------------------------+
      | Species | ID | OGT | DB | Percentage |
      +-----------------------------+-------+-----+-----------+---------------------------------------------------------------------------------------------+
      | Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | E is 8.333003365670164% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
      | Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | R is 6.310991522830762% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
      | Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | A is 10.22668778459711% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
      +-----------------------------+-------+-----+-----------+---------------------------------------------------------------------------------------------+


      Example of desired output



      +-----------------------------+-------+-----+-----------+------------+--------------------------------------------------------------------------------------------+
      | Species | ID | OGT | DB | Amino Acid | Percentage |
      +-----------------------------+-------+-----+-----------+------------+--------------------------------------------------------------------------------------------+
      | Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | E | is 8.333003365670164% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
      | Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | R | is 6.310991522830762% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
      | Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | A | is 10.22668778459711% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
      +-----------------------------+-------+-----+-----------+------------+--------------------------------------------------------------------------------------------+









      share|improve this question















      The problem



      I would like to split a column from a pandas dataframe into 2 columns, in the percentage column (see below), each entry starts with a capitalised alphabet character, I would like to split the 'Percentage' column immediately after this letter, with the new column labelled 'Amino Acid'.



      Current Code:



      import pandas as pd

      df = pd.read_csv('foo.csv')

      df['Amino Acid'], df['Percentage'] = zip(*df['Percentage'].map(lambda x: x.split('[^a-zA-Z]')))

      df.to_csv('bar.csv',index=False)


      Example of input data



      +-----------------------------+-------+-----+-----------+---------------------------------------------------------------------------------------------+
      | Species | ID | OGT | DB | Percentage |
      +-----------------------------+-------+-----+-----------+---------------------------------------------------------------------------------------------+
      | Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | E is 8.333003365670164% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
      | Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | R is 6.310991522830762% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
      | Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | A is 10.22668778459711% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
      +-----------------------------+-------+-----+-----------+---------------------------------------------------------------------------------------------+


      Example of desired output



      +-----------------------------+-------+-----+-----------+------------+--------------------------------------------------------------------------------------------+
      | Species | ID | OGT | DB | Amino Acid | Percentage |
      +-----------------------------+-------+-----+-----------+------------+--------------------------------------------------------------------------------------------+
      | Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | E | is 8.333003365670164% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
      | Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | R | is 6.310991522830762% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
      | Halogeometricum borinquense | 60847 | 37 | ATCC/DSMZ | A | is 10.22668778459711% in ./archaea/GCF_000337855.1/GCF_000337855.1_ASM33785v1_protein.faa |
      +-----------------------------+-------+-----+-----------+------------+--------------------------------------------------------------------------------------------+






      python pandas






      share|improve this question















      share|improve this question













      share|improve this question




      share|improve this question








      edited Nov 19 at 7:13









      Cœur

      17.1k9102140




      17.1k9102140










      asked Jul 9 at 10:44









      Biomage

      908




      908
























          2 Answers
          2






          active

          oldest

          votes

















          up vote
          4
          down vote



          accepted










          Use split be first whitespace:



          df[['Amino Acid', 'Percentage']] = df['Percentage'].str.split(n=1, expand=True)





          share|improve this answer





















          • Do you know how I could also split the string 'archaea' out of the input csv into another column? My input has archaea or bacteria which in that entry
            – Biomage
            Jul 9 at 12:27










          • @Biomage - I think need df[['before_arch', 'after_arch']] = df['Percentage'].str.split('archaea',n=1, expand=True)
            – jezrael
            Jul 9 at 12:46












          • Hmm, in my actual input data I also have some 'bacteria' instead of 'archaea' is there a solution that put either result in it's own column?
            – Biomage
            Jul 9 at 12:48






          • 1




            @Biomage - do you think split by word archaea or bacteria ? Then need .str.split('archaea|bacteria',n=1, expand=True)
            – jezrael
            Jul 9 at 12:49










          • if I try: df['Domain'] = df['Percentage'].str.split('archaea|bacteria',n=1, expand=True) I get a wrong number of items passed error
            – Biomage
            Jul 9 at 12:57


















          up vote
          2
          down vote













          You can extract the first letter directly:



          df['Amino Acid'] = df['Percentage'].str[0]
          df['Percentage'] = df['Percentage'].str[1:]





          share|improve this answer





















            Your Answer






            StackExchange.ifUsing("editor", function () {
            StackExchange.using("externalEditor", function () {
            StackExchange.using("snippets", function () {
            StackExchange.snippets.init();
            });
            });
            }, "code-snippets");

            StackExchange.ready(function() {
            var channelOptions = {
            tags: "".split(" "),
            id: "1"
            };
            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',
            convertImagesToLinks: true,
            noModals: true,
            showLowRepImageUploadWarning: true,
            reputationToPostImages: 10,
            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%2fstackoverflow.com%2fquestions%2f51243702%2fsplitting-pandas-dataframe-column-into-two-after-the-first-letter-in-the-cell%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown

























            2 Answers
            2






            active

            oldest

            votes








            2 Answers
            2






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes








            up vote
            4
            down vote



            accepted










            Use split be first whitespace:



            df[['Amino Acid', 'Percentage']] = df['Percentage'].str.split(n=1, expand=True)





            share|improve this answer





















            • Do you know how I could also split the string 'archaea' out of the input csv into another column? My input has archaea or bacteria which in that entry
              – Biomage
              Jul 9 at 12:27










            • @Biomage - I think need df[['before_arch', 'after_arch']] = df['Percentage'].str.split('archaea',n=1, expand=True)
              – jezrael
              Jul 9 at 12:46












            • Hmm, in my actual input data I also have some 'bacteria' instead of 'archaea' is there a solution that put either result in it's own column?
              – Biomage
              Jul 9 at 12:48






            • 1




              @Biomage - do you think split by word archaea or bacteria ? Then need .str.split('archaea|bacteria',n=1, expand=True)
              – jezrael
              Jul 9 at 12:49










            • if I try: df['Domain'] = df['Percentage'].str.split('archaea|bacteria',n=1, expand=True) I get a wrong number of items passed error
              – Biomage
              Jul 9 at 12:57















            up vote
            4
            down vote



            accepted










            Use split be first whitespace:



            df[['Amino Acid', 'Percentage']] = df['Percentage'].str.split(n=1, expand=True)





            share|improve this answer





















            • Do you know how I could also split the string 'archaea' out of the input csv into another column? My input has archaea or bacteria which in that entry
              – Biomage
              Jul 9 at 12:27










            • @Biomage - I think need df[['before_arch', 'after_arch']] = df['Percentage'].str.split('archaea',n=1, expand=True)
              – jezrael
              Jul 9 at 12:46












            • Hmm, in my actual input data I also have some 'bacteria' instead of 'archaea' is there a solution that put either result in it's own column?
              – Biomage
              Jul 9 at 12:48






            • 1




              @Biomage - do you think split by word archaea or bacteria ? Then need .str.split('archaea|bacteria',n=1, expand=True)
              – jezrael
              Jul 9 at 12:49










            • if I try: df['Domain'] = df['Percentage'].str.split('archaea|bacteria',n=1, expand=True) I get a wrong number of items passed error
              – Biomage
              Jul 9 at 12:57













            up vote
            4
            down vote



            accepted







            up vote
            4
            down vote



            accepted






            Use split be first whitespace:



            df[['Amino Acid', 'Percentage']] = df['Percentage'].str.split(n=1, expand=True)





            share|improve this answer












            Use split be first whitespace:



            df[['Amino Acid', 'Percentage']] = df['Percentage'].str.split(n=1, expand=True)






            share|improve this answer












            share|improve this answer



            share|improve this answer










            answered Jul 9 at 10:47









            jezrael

            311k21247322




            311k21247322












            • Do you know how I could also split the string 'archaea' out of the input csv into another column? My input has archaea or bacteria which in that entry
              – Biomage
              Jul 9 at 12:27










            • @Biomage - I think need df[['before_arch', 'after_arch']] = df['Percentage'].str.split('archaea',n=1, expand=True)
              – jezrael
              Jul 9 at 12:46












            • Hmm, in my actual input data I also have some 'bacteria' instead of 'archaea' is there a solution that put either result in it's own column?
              – Biomage
              Jul 9 at 12:48






            • 1




              @Biomage - do you think split by word archaea or bacteria ? Then need .str.split('archaea|bacteria',n=1, expand=True)
              – jezrael
              Jul 9 at 12:49










            • if I try: df['Domain'] = df['Percentage'].str.split('archaea|bacteria',n=1, expand=True) I get a wrong number of items passed error
              – Biomage
              Jul 9 at 12:57


















            • Do you know how I could also split the string 'archaea' out of the input csv into another column? My input has archaea or bacteria which in that entry
              – Biomage
              Jul 9 at 12:27










            • @Biomage - I think need df[['before_arch', 'after_arch']] = df['Percentage'].str.split('archaea',n=1, expand=True)
              – jezrael
              Jul 9 at 12:46












            • Hmm, in my actual input data I also have some 'bacteria' instead of 'archaea' is there a solution that put either result in it's own column?
              – Biomage
              Jul 9 at 12:48






            • 1




              @Biomage - do you think split by word archaea or bacteria ? Then need .str.split('archaea|bacteria',n=1, expand=True)
              – jezrael
              Jul 9 at 12:49










            • if I try: df['Domain'] = df['Percentage'].str.split('archaea|bacteria',n=1, expand=True) I get a wrong number of items passed error
              – Biomage
              Jul 9 at 12:57
















            Do you know how I could also split the string 'archaea' out of the input csv into another column? My input has archaea or bacteria which in that entry
            – Biomage
            Jul 9 at 12:27




            Do you know how I could also split the string 'archaea' out of the input csv into another column? My input has archaea or bacteria which in that entry
            – Biomage
            Jul 9 at 12:27












            @Biomage - I think need df[['before_arch', 'after_arch']] = df['Percentage'].str.split('archaea',n=1, expand=True)
            – jezrael
            Jul 9 at 12:46






            @Biomage - I think need df[['before_arch', 'after_arch']] = df['Percentage'].str.split('archaea',n=1, expand=True)
            – jezrael
            Jul 9 at 12:46














            Hmm, in my actual input data I also have some 'bacteria' instead of 'archaea' is there a solution that put either result in it's own column?
            – Biomage
            Jul 9 at 12:48




            Hmm, in my actual input data I also have some 'bacteria' instead of 'archaea' is there a solution that put either result in it's own column?
            – Biomage
            Jul 9 at 12:48




            1




            1




            @Biomage - do you think split by word archaea or bacteria ? Then need .str.split('archaea|bacteria',n=1, expand=True)
            – jezrael
            Jul 9 at 12:49




            @Biomage - do you think split by word archaea or bacteria ? Then need .str.split('archaea|bacteria',n=1, expand=True)
            – jezrael
            Jul 9 at 12:49












            if I try: df['Domain'] = df['Percentage'].str.split('archaea|bacteria',n=1, expand=True) I get a wrong number of items passed error
            – Biomage
            Jul 9 at 12:57




            if I try: df['Domain'] = df['Percentage'].str.split('archaea|bacteria',n=1, expand=True) I get a wrong number of items passed error
            – Biomage
            Jul 9 at 12:57












            up vote
            2
            down vote













            You can extract the first letter directly:



            df['Amino Acid'] = df['Percentage'].str[0]
            df['Percentage'] = df['Percentage'].str[1:]





            share|improve this answer

























              up vote
              2
              down vote













              You can extract the first letter directly:



              df['Amino Acid'] = df['Percentage'].str[0]
              df['Percentage'] = df['Percentage'].str[1:]





              share|improve this answer























                up vote
                2
                down vote










                up vote
                2
                down vote









                You can extract the first letter directly:



                df['Amino Acid'] = df['Percentage'].str[0]
                df['Percentage'] = df['Percentage'].str[1:]





                share|improve this answer












                You can extract the first letter directly:



                df['Amino Acid'] = df['Percentage'].str[0]
                df['Percentage'] = df['Percentage'].str[1:]






                share|improve this answer












                share|improve this answer



                share|improve this answer










                answered Jul 9 at 10:47









                jpp

                85.5k194897




                85.5k194897






























                    draft saved

                    draft discarded




















































                    Thanks for contributing an answer to Stack Overflow!


                    • 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.


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





                    Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


                    Please pay close attention to the following guidance:


                    • 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.


                    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%2fstackoverflow.com%2fquestions%2f51243702%2fsplitting-pandas-dataframe-column-into-two-after-the-first-letter-in-the-cell%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

                    "Incorrect syntax near the keyword 'ON'. (on update cascade, on delete cascade,)

                    Alcedinidae

                    Origin of the phrase “under your belt”?