How to read numbers in python from csv file?

Question

I have a csv file and I have to compute the mean for some of the columns. That\'s how I did:

file=csv.reader(open(\'tab.csv\',\'r\'))
n=[]
for row in file:
          


        

Answer 1

Just add quoting:

with open('tab.csv', newline='') as file:
    reader = csv.reader(file, quoting=csv.QUOTE_NONNUMERIC)
    n=[]
    for row in reader:
        n.append(row[8])

Answer 2

Just cast as you append:

 n.append(float(row[8]))

If there are empty strings catch those before appending.

try:
    n.append(float(row[8]))
except ValueError:
   continue

Or you might want to try pandas, in particular pandas.read_csv:

import pandas as pd

df = pd.read_csv("in.csv")
print(df["col_name"].mean())