Python：我的csv.reader以文本形式导入csv文件

Question

After importing CSV file, the output appears like [['1', '2', '3']] . How can I make sure it is imported as a number?

Answer 1

With the csv module reader function a row read from the csv file is returned as a list of strings. If you want unquoted numbers not to be returned as strings use the quoting=csv.QUOTE_NONNUMERIC option. However, be aware that this option will convert to float. If you want to process or display these numbers as int s then you will have to cast them as int .

This is your csv file:

1,2,3
4,5,6
7,8,9

Assuming you want a list of lists output:

import csv                                                                                                                                    
tst = open('test.csv')                                                                                                                          
l = []                                                                                                                                          
reader = csv.reader(tst, quoting=csv.QUOTE_NONNUMERIC)                                                                                         
for line in reader:                                                                                                                           
    l.append(line)

print l

Yields:

[[1.0, 2.0, 3.0], [4.0, 5.0, 6.0], [7.0, 8.0, 9.0]]

To output integers, you might as well convert the strings to integers directly:

l = []                                                                                                                                          
tst = open('test.csv')                                                                                                                          
reader = csv.reader(tst)                                                                                                                      
for line in reader:                                                                                                                           
    l.append([int(i) for i in line])                                                                                                          

print l 

Yields:

[[1, 2, 3], [4, 5, 6], [7, 8, 9]]