Fill data from column X to Column Y if Y has NaN using python












1















I have a column say X with some data. I want to move this data into another Column say Y. I got the code to do it.



This shows column X and Y # in Column Y meaning NAN
The code is as below:



id = df['X'].str.extract(r"(d[8]sd[2])",expand=False).tolist() #extracting values which look like 12345678s12 and i include NaN values 

df_new= pd.DataFrame({'Y':id})
wb = load_workbook('text.xlsx')
ws = wb['Sheet1']
for index, row in df_new.iterrows():
cell = 'Y%d' % (index + 2)
ws[cell] = row[0]
wb.save('text.xlsx')


The problem I'm facing is there is some data in Column Y and code overwrites the whole column Y with id.
I don't want this to happen.I want to retain the data in column Y and only if there are NaN values in it, I want those to be replaced by the corresponding value of id.










share|improve this question

























  • Do you want to replace values from x to y where y contains #?

    – Mohamed Thasin ah
    Nov 23 '18 at 10:55











  • Yes thats what is my expected output

    – Adarsh Bhansali
    Nov 23 '18 at 10:57
















1















I have a column say X with some data. I want to move this data into another Column say Y. I got the code to do it.



This shows column X and Y # in Column Y meaning NAN
The code is as below:



id = df['X'].str.extract(r"(d[8]sd[2])",expand=False).tolist() #extracting values which look like 12345678s12 and i include NaN values 

df_new= pd.DataFrame({'Y':id})
wb = load_workbook('text.xlsx')
ws = wb['Sheet1']
for index, row in df_new.iterrows():
cell = 'Y%d' % (index + 2)
ws[cell] = row[0]
wb.save('text.xlsx')


The problem I'm facing is there is some data in Column Y and code overwrites the whole column Y with id.
I don't want this to happen.I want to retain the data in column Y and only if there are NaN values in it, I want those to be replaced by the corresponding value of id.










share|improve this question

























  • Do you want to replace values from x to y where y contains #?

    – Mohamed Thasin ah
    Nov 23 '18 at 10:55











  • Yes thats what is my expected output

    – Adarsh Bhansali
    Nov 23 '18 at 10:57














1












1








1








I have a column say X with some data. I want to move this data into another Column say Y. I got the code to do it.



This shows column X and Y # in Column Y meaning NAN
The code is as below:



id = df['X'].str.extract(r"(d[8]sd[2])",expand=False).tolist() #extracting values which look like 12345678s12 and i include NaN values 

df_new= pd.DataFrame({'Y':id})
wb = load_workbook('text.xlsx')
ws = wb['Sheet1']
for index, row in df_new.iterrows():
cell = 'Y%d' % (index + 2)
ws[cell] = row[0]
wb.save('text.xlsx')


The problem I'm facing is there is some data in Column Y and code overwrites the whole column Y with id.
I don't want this to happen.I want to retain the data in column Y and only if there are NaN values in it, I want those to be replaced by the corresponding value of id.










share|improve this question
















I have a column say X with some data. I want to move this data into another Column say Y. I got the code to do it.



This shows column X and Y # in Column Y meaning NAN
The code is as below:



id = df['X'].str.extract(r"(d[8]sd[2])",expand=False).tolist() #extracting values which look like 12345678s12 and i include NaN values 

df_new= pd.DataFrame({'Y':id})
wb = load_workbook('text.xlsx')
ws = wb['Sheet1']
for index, row in df_new.iterrows():
cell = 'Y%d' % (index + 2)
ws[cell] = row[0]
wb.save('text.xlsx')


The problem I'm facing is there is some data in Column Y and code overwrites the whole column Y with id.
I don't want this to happen.I want to retain the data in column Y and only if there are NaN values in it, I want those to be replaced by the corresponding value of id.







python excel pandas nan






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Nov 23 '18 at 11:01









Anubhav Singh

143212




143212










asked Nov 23 '18 at 10:49









Adarsh BhansaliAdarsh Bhansali

84




84













  • Do you want to replace values from x to y where y contains #?

    – Mohamed Thasin ah
    Nov 23 '18 at 10:55











  • Yes thats what is my expected output

    – Adarsh Bhansali
    Nov 23 '18 at 10:57



















  • Do you want to replace values from x to y where y contains #?

    – Mohamed Thasin ah
    Nov 23 '18 at 10:55











  • Yes thats what is my expected output

    – Adarsh Bhansali
    Nov 23 '18 at 10:57

















Do you want to replace values from x to y where y contains #?

– Mohamed Thasin ah
Nov 23 '18 at 10:55





Do you want to replace values from x to y where y contains #?

– Mohamed Thasin ah
Nov 23 '18 at 10:55













Yes thats what is my expected output

– Adarsh Bhansali
Nov 23 '18 at 10:57





Yes thats what is my expected output

– Adarsh Bhansali
Nov 23 '18 at 10:57












4 Answers
4






active

oldest

votes


















1














mask



You can mask one series with another:



df['Y'].mask(df['Y'] == '#', df['X'], inplace=True)


Here's a demo with the version which does not work in place:



df = pd.DataFrame({'X': ['A', 'B', 'C', 'D', 'E'],
'Y': ['#', '1', '2', '#', '3']})

df['Y'] = df['Y'].mask(df['Y'] == '#', df['X'])

print(df)

X Y
0 A A
1 B 1
2 C 2
3 D D
4 E 3





share|improve this answer
























  • Incase if there was a blank in place of # how would the code change ?

    – Adarsh Bhansali
    Nov 23 '18 at 11:09











  • If by blank you mean empty string, use df['Y'].isin(['#', '']) for your Boolean condition. If you mean null value (NaN), use df['Y'].isnull() | df['Y'].eq('#').

    – jpp
    Nov 23 '18 at 11:10













  • thanks.. but how do i transfer it back to the excel file and in place of df['X'] can i use id so that i can just give the extracted data.

    – Adarsh Bhansali
    Nov 23 '18 at 11:20











  • @AdarshBhansali, You are asking at least 3 questions there. If you have another question, please ask a new question.

    – jpp
    Nov 23 '18 at 11:23



















2














You can use:



df['Y'] = np.where(df['Y']=='#', df['X'], df['Y'])





share|improve this answer































    1














    Use np.where



    df['Y'] = np.where(df['Y'] == '#', df['X'], df['Y'])





    share|improve this answer































      0














      .loc



      Do you want to replace values from x to y where y contains #



      If So try this,



      df.loc[df['Y']=='#','Y']=df['X']


      As your objective is only want to replace records where Y has #, So mask or lock the index where Y has # then assign values from X to Y to only locked index.



      If you want to deal with blank then,



      df.loc[df['Y'].isnull(),'Y']=df['X']





      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',
        autoActivateHeartbeat: false,
        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%2f53445242%2ffill-data-from-column-x-to-column-y-if-y-has-nan-using-python%23new-answer', 'question_page');
        }
        );

        Post as a guest















        Required, but never shown

























        4 Answers
        4






        active

        oldest

        votes








        4 Answers
        4






        active

        oldest

        votes









        active

        oldest

        votes






        active

        oldest

        votes









        1














        mask



        You can mask one series with another:



        df['Y'].mask(df['Y'] == '#', df['X'], inplace=True)


        Here's a demo with the version which does not work in place:



        df = pd.DataFrame({'X': ['A', 'B', 'C', 'D', 'E'],
        'Y': ['#', '1', '2', '#', '3']})

        df['Y'] = df['Y'].mask(df['Y'] == '#', df['X'])

        print(df)

        X Y
        0 A A
        1 B 1
        2 C 2
        3 D D
        4 E 3





        share|improve this answer
























        • Incase if there was a blank in place of # how would the code change ?

          – Adarsh Bhansali
          Nov 23 '18 at 11:09











        • If by blank you mean empty string, use df['Y'].isin(['#', '']) for your Boolean condition. If you mean null value (NaN), use df['Y'].isnull() | df['Y'].eq('#').

          – jpp
          Nov 23 '18 at 11:10













        • thanks.. but how do i transfer it back to the excel file and in place of df['X'] can i use id so that i can just give the extracted data.

          – Adarsh Bhansali
          Nov 23 '18 at 11:20











        • @AdarshBhansali, You are asking at least 3 questions there. If you have another question, please ask a new question.

          – jpp
          Nov 23 '18 at 11:23
















        1














        mask



        You can mask one series with another:



        df['Y'].mask(df['Y'] == '#', df['X'], inplace=True)


        Here's a demo with the version which does not work in place:



        df = pd.DataFrame({'X': ['A', 'B', 'C', 'D', 'E'],
        'Y': ['#', '1', '2', '#', '3']})

        df['Y'] = df['Y'].mask(df['Y'] == '#', df['X'])

        print(df)

        X Y
        0 A A
        1 B 1
        2 C 2
        3 D D
        4 E 3





        share|improve this answer
























        • Incase if there was a blank in place of # how would the code change ?

          – Adarsh Bhansali
          Nov 23 '18 at 11:09











        • If by blank you mean empty string, use df['Y'].isin(['#', '']) for your Boolean condition. If you mean null value (NaN), use df['Y'].isnull() | df['Y'].eq('#').

          – jpp
          Nov 23 '18 at 11:10













        • thanks.. but how do i transfer it back to the excel file and in place of df['X'] can i use id so that i can just give the extracted data.

          – Adarsh Bhansali
          Nov 23 '18 at 11:20











        • @AdarshBhansali, You are asking at least 3 questions there. If you have another question, please ask a new question.

          – jpp
          Nov 23 '18 at 11:23














        1












        1








        1







        mask



        You can mask one series with another:



        df['Y'].mask(df['Y'] == '#', df['X'], inplace=True)


        Here's a demo with the version which does not work in place:



        df = pd.DataFrame({'X': ['A', 'B', 'C', 'D', 'E'],
        'Y': ['#', '1', '2', '#', '3']})

        df['Y'] = df['Y'].mask(df['Y'] == '#', df['X'])

        print(df)

        X Y
        0 A A
        1 B 1
        2 C 2
        3 D D
        4 E 3





        share|improve this answer













        mask



        You can mask one series with another:



        df['Y'].mask(df['Y'] == '#', df['X'], inplace=True)


        Here's a demo with the version which does not work in place:



        df = pd.DataFrame({'X': ['A', 'B', 'C', 'D', 'E'],
        'Y': ['#', '1', '2', '#', '3']})

        df['Y'] = df['Y'].mask(df['Y'] == '#', df['X'])

        print(df)

        X Y
        0 A A
        1 B 1
        2 C 2
        3 D D
        4 E 3






        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Nov 23 '18 at 10:56









        jppjpp

        94.1k2155106




        94.1k2155106













        • Incase if there was a blank in place of # how would the code change ?

          – Adarsh Bhansali
          Nov 23 '18 at 11:09











        • If by blank you mean empty string, use df['Y'].isin(['#', '']) for your Boolean condition. If you mean null value (NaN), use df['Y'].isnull() | df['Y'].eq('#').

          – jpp
          Nov 23 '18 at 11:10













        • thanks.. but how do i transfer it back to the excel file and in place of df['X'] can i use id so that i can just give the extracted data.

          – Adarsh Bhansali
          Nov 23 '18 at 11:20











        • @AdarshBhansali, You are asking at least 3 questions there. If you have another question, please ask a new question.

          – jpp
          Nov 23 '18 at 11:23



















        • Incase if there was a blank in place of # how would the code change ?

          – Adarsh Bhansali
          Nov 23 '18 at 11:09











        • If by blank you mean empty string, use df['Y'].isin(['#', '']) for your Boolean condition. If you mean null value (NaN), use df['Y'].isnull() | df['Y'].eq('#').

          – jpp
          Nov 23 '18 at 11:10













        • thanks.. but how do i transfer it back to the excel file and in place of df['X'] can i use id so that i can just give the extracted data.

          – Adarsh Bhansali
          Nov 23 '18 at 11:20











        • @AdarshBhansali, You are asking at least 3 questions there. If you have another question, please ask a new question.

          – jpp
          Nov 23 '18 at 11:23

















        Incase if there was a blank in place of # how would the code change ?

        – Adarsh Bhansali
        Nov 23 '18 at 11:09





        Incase if there was a blank in place of # how would the code change ?

        – Adarsh Bhansali
        Nov 23 '18 at 11:09













        If by blank you mean empty string, use df['Y'].isin(['#', '']) for your Boolean condition. If you mean null value (NaN), use df['Y'].isnull() | df['Y'].eq('#').

        – jpp
        Nov 23 '18 at 11:10







        If by blank you mean empty string, use df['Y'].isin(['#', '']) for your Boolean condition. If you mean null value (NaN), use df['Y'].isnull() | df['Y'].eq('#').

        – jpp
        Nov 23 '18 at 11:10















        thanks.. but how do i transfer it back to the excel file and in place of df['X'] can i use id so that i can just give the extracted data.

        – Adarsh Bhansali
        Nov 23 '18 at 11:20





        thanks.. but how do i transfer it back to the excel file and in place of df['X'] can i use id so that i can just give the extracted data.

        – Adarsh Bhansali
        Nov 23 '18 at 11:20













        @AdarshBhansali, You are asking at least 3 questions there. If you have another question, please ask a new question.

        – jpp
        Nov 23 '18 at 11:23





        @AdarshBhansali, You are asking at least 3 questions there. If you have another question, please ask a new question.

        – jpp
        Nov 23 '18 at 11:23













        2














        You can use:



        df['Y'] = np.where(df['Y']=='#', df['X'], df['Y'])





        share|improve this answer




























          2














          You can use:



          df['Y'] = np.where(df['Y']=='#', df['X'], df['Y'])





          share|improve this answer


























            2












            2








            2







            You can use:



            df['Y'] = np.where(df['Y']=='#', df['X'], df['Y'])





            share|improve this answer













            You can use:



            df['Y'] = np.where(df['Y']=='#', df['X'], df['Y'])






            share|improve this answer












            share|improve this answer



            share|improve this answer










            answered Nov 23 '18 at 10:58









            JoeJoe

            5,89621129




            5,89621129























                1














                Use np.where



                df['Y'] = np.where(df['Y'] == '#', df['X'], df['Y'])





                share|improve this answer




























                  1














                  Use np.where



                  df['Y'] = np.where(df['Y'] == '#', df['X'], df['Y'])





                  share|improve this answer


























                    1












                    1








                    1







                    Use np.where



                    df['Y'] = np.where(df['Y'] == '#', df['X'], df['Y'])





                    share|improve this answer













                    Use np.where



                    df['Y'] = np.where(df['Y'] == '#', df['X'], df['Y'])






                    share|improve this answer












                    share|improve this answer



                    share|improve this answer










                    answered Nov 23 '18 at 10:58









                    SociopathSociopath

                    3,64281635




                    3,64281635























                        0














                        .loc



                        Do you want to replace values from x to y where y contains #



                        If So try this,



                        df.loc[df['Y']=='#','Y']=df['X']


                        As your objective is only want to replace records where Y has #, So mask or lock the index where Y has # then assign values from X to Y to only locked index.



                        If you want to deal with blank then,



                        df.loc[df['Y'].isnull(),'Y']=df['X']





                        share|improve this answer






























                          0














                          .loc



                          Do you want to replace values from x to y where y contains #



                          If So try this,



                          df.loc[df['Y']=='#','Y']=df['X']


                          As your objective is only want to replace records where Y has #, So mask or lock the index where Y has # then assign values from X to Y to only locked index.



                          If you want to deal with blank then,



                          df.loc[df['Y'].isnull(),'Y']=df['X']





                          share|improve this answer




























                            0












                            0








                            0







                            .loc



                            Do you want to replace values from x to y where y contains #



                            If So try this,



                            df.loc[df['Y']=='#','Y']=df['X']


                            As your objective is only want to replace records where Y has #, So mask or lock the index where Y has # then assign values from X to Y to only locked index.



                            If you want to deal with blank then,



                            df.loc[df['Y'].isnull(),'Y']=df['X']





                            share|improve this answer















                            .loc



                            Do you want to replace values from x to y where y contains #



                            If So try this,



                            df.loc[df['Y']=='#','Y']=df['X']


                            As your objective is only want to replace records where Y has #, So mask or lock the index where Y has # then assign values from X to Y to only locked index.



                            If you want to deal with blank then,



                            df.loc[df['Y'].isnull(),'Y']=df['X']






                            share|improve this answer














                            share|improve this answer



                            share|improve this answer








                            edited Nov 23 '18 at 11:10

























                            answered Nov 23 '18 at 10:56









                            Mohamed Thasin ahMohamed Thasin ah

                            3,49331239




                            3,49331239






























                                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.




                                draft saved


                                draft discarded














                                StackExchange.ready(
                                function () {
                                StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53445242%2ffill-data-from-column-x-to-column-y-if-y-has-nan-using-python%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

                                Berounka

                                Sphinx de Gizeh

                                Different font size/position of beamer's navigation symbols template's content depending on regular/plain...