Pandas-选择具有特定值的列

Question

I have a huge csv file and i want to filter out the dataframes with a specific value.

dataf = pd.read_csv('table.txt', sep=',')
dataf[(dataf.Subject_code == '100')]
#print (dataf[(dataf.Subject_code =='100')])

It returns an empty data frame. I get only the headers of the file. I need all the dataframes whose subject code is equal to 100.

Student Subject_code Score 1 100 A 10 500 B 12 100 A 15 100 C

Answer 1

Pandas most likely converts strings representing numbers to numbers (you can find out by doing dataf.info() and see if the column is numeric or Object . If it does, you should do equality check against 100 not "100" .

Answer 2

Use this:

print(dataf[dataf.Subject_code == 100])