Remove any empty fields in a loop?












3















A list has many paths of certain csv's.
How to check if each csv in every loop has any empty columns and delete them if they are.



Code:



for i in list1:
if (list1.columns = '').any():
i.remove that column


Hope this explains what I am talking about.










share|improve this question



























    3















    A list has many paths of certain csv's.
    How to check if each csv in every loop has any empty columns and delete them if they are.



    Code:



    for i in list1:
    if (list1.columns = '').any():
    i.remove that column


    Hope this explains what I am talking about.










    share|improve this question

























      3












      3








      3








      A list has many paths of certain csv's.
      How to check if each csv in every loop has any empty columns and delete them if they are.



      Code:



      for i in list1:
      if (list1.columns = '').any():
      i.remove that column


      Hope this explains what I am talking about.










      share|improve this question














      A list has many paths of certain csv's.
      How to check if each csv in every loop has any empty columns and delete them if they are.



      Code:



      for i in list1:
      if (list1.columns = '').any():
      i.remove that column


      Hope this explains what I am talking about.







      python pandas






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked Nov 20 '18 at 11:30









      user10671234user10671234

      376




      376
























          1 Answer
          1






          active

          oldest

          votes


















          3














          Sample:



          df = pd.DataFrame({
          '':list('abcdef'),
          'B':[4,5,4,5,5,np.nan],
          'C':[''] * 6,
          'D':[np.nan] * 6,
          'E':[5,3,6,9,2,4],
          'F':list('aaabb') + ['']
          })

          print (df)
          B C D E F
          0 a 4.0 NaN 5 a
          1 b 5.0 NaN 3 a
          2 c 4.0 NaN 6 a
          3 d 5.0 NaN 9 b
          4 e 5.0 NaN 2 b
          5 f NaN NaN 4


          Removed first column, because empty column name - it means filtering only columns with no empty values with loc and boolean indexing:



          df1 = df.loc[:, df.columns != '']
          print (df1)
          B C D E F
          0 4.0 NaN 5 a
          1 5.0 NaN 3 a
          2 4.0 NaN 6 a
          3 5.0 NaN 9 b
          4 5.0 NaN 2 b
          5 NaN NaN 4


          Reoved column C, because filled only empty values - compare all values if not empty values and get at least one True per column by DataFrame.any, also filter by boolean indexing with loc:



          df2 = df.loc[:, (df != '').any()]
          print (df2)
          B D E
          0 a 4.0 NaN 5
          1 b 5.0 NaN 3
          2 c 4.0 NaN 6
          3 d 5.0 NaN 9
          4 e 5.0 NaN 2
          5 f NaN NaN 4

          print ((df != ''))
          B C D E F
          0 True True False True True True
          1 True True False True True True
          2 True True False True True True
          3 True True False True True True
          4 True True False True True True
          5 True True False True True False

          print ((df != '').any())
          True
          B True
          C False
          D True
          E True
          F True
          dtype: bool


          Removed column D because filled only missing values with function dropna:



          df3 = df.dropna(axis=1, how='all')
          print (df3)
          B C E F
          0 a 4.0 5 a
          1 b 5.0 3 a
          2 c 4.0 6 a
          3 d 5.0 9 b
          4 e 5.0 2 b
          5 f NaN 4





          share|improve this answer


























          • The first filters out columns that may not be empty but have empty field name?

            – user10671234
            Nov 20 '18 at 11:35











          • @user10671234 - added sample.

            – jezrael
            Nov 20 '18 at 11:38






          • 1





            upvoted and accepted thanks

            – user10671234
            Nov 20 '18 at 11:44






          • 1





            @user10671234 - thank you.

            – jezrael
            Nov 20 '18 at 11:45






          • 1





            ok understood now.

            – user10671234
            Nov 20 '18 at 12:49











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          1 Answer
          1






          active

          oldest

          votes








          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          3














          Sample:



          df = pd.DataFrame({
          '':list('abcdef'),
          'B':[4,5,4,5,5,np.nan],
          'C':[''] * 6,
          'D':[np.nan] * 6,
          'E':[5,3,6,9,2,4],
          'F':list('aaabb') + ['']
          })

          print (df)
          B C D E F
          0 a 4.0 NaN 5 a
          1 b 5.0 NaN 3 a
          2 c 4.0 NaN 6 a
          3 d 5.0 NaN 9 b
          4 e 5.0 NaN 2 b
          5 f NaN NaN 4


          Removed first column, because empty column name - it means filtering only columns with no empty values with loc and boolean indexing:



          df1 = df.loc[:, df.columns != '']
          print (df1)
          B C D E F
          0 4.0 NaN 5 a
          1 5.0 NaN 3 a
          2 4.0 NaN 6 a
          3 5.0 NaN 9 b
          4 5.0 NaN 2 b
          5 NaN NaN 4


          Reoved column C, because filled only empty values - compare all values if not empty values and get at least one True per column by DataFrame.any, also filter by boolean indexing with loc:



          df2 = df.loc[:, (df != '').any()]
          print (df2)
          B D E
          0 a 4.0 NaN 5
          1 b 5.0 NaN 3
          2 c 4.0 NaN 6
          3 d 5.0 NaN 9
          4 e 5.0 NaN 2
          5 f NaN NaN 4

          print ((df != ''))
          B C D E F
          0 True True False True True True
          1 True True False True True True
          2 True True False True True True
          3 True True False True True True
          4 True True False True True True
          5 True True False True True False

          print ((df != '').any())
          True
          B True
          C False
          D True
          E True
          F True
          dtype: bool


          Removed column D because filled only missing values with function dropna:



          df3 = df.dropna(axis=1, how='all')
          print (df3)
          B C E F
          0 a 4.0 5 a
          1 b 5.0 3 a
          2 c 4.0 6 a
          3 d 5.0 9 b
          4 e 5.0 2 b
          5 f NaN 4





          share|improve this answer


























          • The first filters out columns that may not be empty but have empty field name?

            – user10671234
            Nov 20 '18 at 11:35











          • @user10671234 - added sample.

            – jezrael
            Nov 20 '18 at 11:38






          • 1





            upvoted and accepted thanks

            – user10671234
            Nov 20 '18 at 11:44






          • 1





            @user10671234 - thank you.

            – jezrael
            Nov 20 '18 at 11:45






          • 1





            ok understood now.

            – user10671234
            Nov 20 '18 at 12:49
















          3














          Sample:



          df = pd.DataFrame({
          '':list('abcdef'),
          'B':[4,5,4,5,5,np.nan],
          'C':[''] * 6,
          'D':[np.nan] * 6,
          'E':[5,3,6,9,2,4],
          'F':list('aaabb') + ['']
          })

          print (df)
          B C D E F
          0 a 4.0 NaN 5 a
          1 b 5.0 NaN 3 a
          2 c 4.0 NaN 6 a
          3 d 5.0 NaN 9 b
          4 e 5.0 NaN 2 b
          5 f NaN NaN 4


          Removed first column, because empty column name - it means filtering only columns with no empty values with loc and boolean indexing:



          df1 = df.loc[:, df.columns != '']
          print (df1)
          B C D E F
          0 4.0 NaN 5 a
          1 5.0 NaN 3 a
          2 4.0 NaN 6 a
          3 5.0 NaN 9 b
          4 5.0 NaN 2 b
          5 NaN NaN 4


          Reoved column C, because filled only empty values - compare all values if not empty values and get at least one True per column by DataFrame.any, also filter by boolean indexing with loc:



          df2 = df.loc[:, (df != '').any()]
          print (df2)
          B D E
          0 a 4.0 NaN 5
          1 b 5.0 NaN 3
          2 c 4.0 NaN 6
          3 d 5.0 NaN 9
          4 e 5.0 NaN 2
          5 f NaN NaN 4

          print ((df != ''))
          B C D E F
          0 True True False True True True
          1 True True False True True True
          2 True True False True True True
          3 True True False True True True
          4 True True False True True True
          5 True True False True True False

          print ((df != '').any())
          True
          B True
          C False
          D True
          E True
          F True
          dtype: bool


          Removed column D because filled only missing values with function dropna:



          df3 = df.dropna(axis=1, how='all')
          print (df3)
          B C E F
          0 a 4.0 5 a
          1 b 5.0 3 a
          2 c 4.0 6 a
          3 d 5.0 9 b
          4 e 5.0 2 b
          5 f NaN 4





          share|improve this answer


























          • The first filters out columns that may not be empty but have empty field name?

            – user10671234
            Nov 20 '18 at 11:35











          • @user10671234 - added sample.

            – jezrael
            Nov 20 '18 at 11:38






          • 1





            upvoted and accepted thanks

            – user10671234
            Nov 20 '18 at 11:44






          • 1





            @user10671234 - thank you.

            – jezrael
            Nov 20 '18 at 11:45






          • 1





            ok understood now.

            – user10671234
            Nov 20 '18 at 12:49














          3












          3








          3







          Sample:



          df = pd.DataFrame({
          '':list('abcdef'),
          'B':[4,5,4,5,5,np.nan],
          'C':[''] * 6,
          'D':[np.nan] * 6,
          'E':[5,3,6,9,2,4],
          'F':list('aaabb') + ['']
          })

          print (df)
          B C D E F
          0 a 4.0 NaN 5 a
          1 b 5.0 NaN 3 a
          2 c 4.0 NaN 6 a
          3 d 5.0 NaN 9 b
          4 e 5.0 NaN 2 b
          5 f NaN NaN 4


          Removed first column, because empty column name - it means filtering only columns with no empty values with loc and boolean indexing:



          df1 = df.loc[:, df.columns != '']
          print (df1)
          B C D E F
          0 4.0 NaN 5 a
          1 5.0 NaN 3 a
          2 4.0 NaN 6 a
          3 5.0 NaN 9 b
          4 5.0 NaN 2 b
          5 NaN NaN 4


          Reoved column C, because filled only empty values - compare all values if not empty values and get at least one True per column by DataFrame.any, also filter by boolean indexing with loc:



          df2 = df.loc[:, (df != '').any()]
          print (df2)
          B D E
          0 a 4.0 NaN 5
          1 b 5.0 NaN 3
          2 c 4.0 NaN 6
          3 d 5.0 NaN 9
          4 e 5.0 NaN 2
          5 f NaN NaN 4

          print ((df != ''))
          B C D E F
          0 True True False True True True
          1 True True False True True True
          2 True True False True True True
          3 True True False True True True
          4 True True False True True True
          5 True True False True True False

          print ((df != '').any())
          True
          B True
          C False
          D True
          E True
          F True
          dtype: bool


          Removed column D because filled only missing values with function dropna:



          df3 = df.dropna(axis=1, how='all')
          print (df3)
          B C E F
          0 a 4.0 5 a
          1 b 5.0 3 a
          2 c 4.0 6 a
          3 d 5.0 9 b
          4 e 5.0 2 b
          5 f NaN 4





          share|improve this answer















          Sample:



          df = pd.DataFrame({
          '':list('abcdef'),
          'B':[4,5,4,5,5,np.nan],
          'C':[''] * 6,
          'D':[np.nan] * 6,
          'E':[5,3,6,9,2,4],
          'F':list('aaabb') + ['']
          })

          print (df)
          B C D E F
          0 a 4.0 NaN 5 a
          1 b 5.0 NaN 3 a
          2 c 4.0 NaN 6 a
          3 d 5.0 NaN 9 b
          4 e 5.0 NaN 2 b
          5 f NaN NaN 4


          Removed first column, because empty column name - it means filtering only columns with no empty values with loc and boolean indexing:



          df1 = df.loc[:, df.columns != '']
          print (df1)
          B C D E F
          0 4.0 NaN 5 a
          1 5.0 NaN 3 a
          2 4.0 NaN 6 a
          3 5.0 NaN 9 b
          4 5.0 NaN 2 b
          5 NaN NaN 4


          Reoved column C, because filled only empty values - compare all values if not empty values and get at least one True per column by DataFrame.any, also filter by boolean indexing with loc:



          df2 = df.loc[:, (df != '').any()]
          print (df2)
          B D E
          0 a 4.0 NaN 5
          1 b 5.0 NaN 3
          2 c 4.0 NaN 6
          3 d 5.0 NaN 9
          4 e 5.0 NaN 2
          5 f NaN NaN 4

          print ((df != ''))
          B C D E F
          0 True True False True True True
          1 True True False True True True
          2 True True False True True True
          3 True True False True True True
          4 True True False True True True
          5 True True False True True False

          print ((df != '').any())
          True
          B True
          C False
          D True
          E True
          F True
          dtype: bool


          Removed column D because filled only missing values with function dropna:



          df3 = df.dropna(axis=1, how='all')
          print (df3)
          B C E F
          0 a 4.0 5 a
          1 b 5.0 3 a
          2 c 4.0 6 a
          3 d 5.0 9 b
          4 e 5.0 2 b
          5 f NaN 4






          share|improve this answer














          share|improve this answer



          share|improve this answer








          edited Nov 20 '18 at 11:47

























          answered Nov 20 '18 at 11:32









          jezraeljezrael

          327k23270348




          327k23270348













          • The first filters out columns that may not be empty but have empty field name?

            – user10671234
            Nov 20 '18 at 11:35











          • @user10671234 - added sample.

            – jezrael
            Nov 20 '18 at 11:38






          • 1





            upvoted and accepted thanks

            – user10671234
            Nov 20 '18 at 11:44






          • 1





            @user10671234 - thank you.

            – jezrael
            Nov 20 '18 at 11:45






          • 1





            ok understood now.

            – user10671234
            Nov 20 '18 at 12:49



















          • The first filters out columns that may not be empty but have empty field name?

            – user10671234
            Nov 20 '18 at 11:35











          • @user10671234 - added sample.

            – jezrael
            Nov 20 '18 at 11:38






          • 1





            upvoted and accepted thanks

            – user10671234
            Nov 20 '18 at 11:44






          • 1





            @user10671234 - thank you.

            – jezrael
            Nov 20 '18 at 11:45






          • 1





            ok understood now.

            – user10671234
            Nov 20 '18 at 12:49

















          The first filters out columns that may not be empty but have empty field name?

          – user10671234
          Nov 20 '18 at 11:35





          The first filters out columns that may not be empty but have empty field name?

          – user10671234
          Nov 20 '18 at 11:35













          @user10671234 - added sample.

          – jezrael
          Nov 20 '18 at 11:38





          @user10671234 - added sample.

          – jezrael
          Nov 20 '18 at 11:38




          1




          1





          upvoted and accepted thanks

          – user10671234
          Nov 20 '18 at 11:44





          upvoted and accepted thanks

          – user10671234
          Nov 20 '18 at 11:44




          1




          1





          @user10671234 - thank you.

          – jezrael
          Nov 20 '18 at 11:45





          @user10671234 - thank you.

          – jezrael
          Nov 20 '18 at 11:45




          1




          1





          ok understood now.

          – user10671234
          Nov 20 '18 at 12:49





          ok understood now.

          – user10671234
          Nov 20 '18 at 12:49


















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