使用Pandas将数据写入python中的特定列

Question

I have an Excel Sheet where for some of the columns uniqueidentifier is set to "yes" and for rest of them it is blank.

Using the Pandas library , I get the data that have no value in uniqueidentifier using the following command:

df=pandas.read_excel("sample.xlsx")
df=df[df.uniqueidentifier != "yes"]

I then want to write "yes" to the uniqueidenfier column every time I loop through the index in the excel file.

list=[]
for i in df.index
  list.append(df['Subject'][i])
  # do some function here
  var="some value"

Every time I get the proper values in list and in var for the respective index. I want my function to write something to the uniqueidentifier column for that i value in the loop (for example, if in row 4, then when uniqueidentifier is not set, the list should take the value from the subject and append and write "yes" to uniqueidentifier column)

In addition to the above, I want to write the var value to an adjacent column in the excel file.

Could someone help me as I am new to python and stuck here?

Answer 1

to set the unique identifier to be yes you can add to your loop the foloowing line:

if [#some conditions are met]:    
    df.loc[i,'uniqueidentifier']='YES'
    df.iloc[i].new_column=var
    #new_column is the name of the column where you write your var value. you can name it however you want.

then you need to export it back to excel. you can use:

writer = pd.ExcelWriter('file.xlsx')
df.to_excel(writer,'Sheet1')
writer.save()

but keep in mind this will overwrite your old excel