如何使用熊猫重新格式化数据框？

Question

I have the following dataframe:

data = {'Names':['Abbey','English','Maths','Billy','English','Maths','Charlie','English','Maths'],'Subject Grade':['Student Name',85,91,'Student Name',82,74,'Student Name',83,96]}

df = pd.DataFrame(data, columns = ['Names','Subject Grade'])

I would like to reformat the dataframe in order for the names, subject and grades to all be in their respective columns as follows:

data2 = {'Names':['Abbey','Abbey','Billy','Billy','Charlie','Charlie'],'Subject':['English','Maths','English','Maths','English','Maths'],'Grade':[85,91,82,74,83,96]}

df2 = pd.DataFrame(data2, columns = ['Names','Subject','Grade'])

Answer 1

Hi you can use those instructions :

  df['name'] = df['Names'].mask(df['Subject Grade'] != "Student Name")
  df['name'] = df['name'].fillna(method='ffill')
  df = df.query('`Subject Grade`!="Student Name"')
  df = df.rename(columns={'Names':'Subject', 'Subject Grade':'Grade', 'name':'Names'})