如何在讀取CSV文件時將字符串值轉換爲整數值？

Question

打開CSV文件時，整數列將被轉換爲字符串值（'1'，'23'等）。通過循環將其轉換回整數的最佳方式是什麼？

import csv 

with open('C:/Python27/testweight.csv', 'rb') as f: 
    reader = csv.reader(f) 
    rows = [row for row in reader if row[1] > 's'] 

for row in rows: 
    print row 

CSV文件如下：

Account Value 
ABC  6 
DEF  3 
GHI  4 
JKL  7 

Answer 1

我想這你想要做什麼：

import csv 

with open('C:/Python27/testweight.csv', 'rb') as f: 
    reader = csv.reader(f, delimiter='\t') 
    header = next(reader) 
    rows = [header] + [[row[0], int(row[1])] for row in reader] 

for row in rows: 
    print row 

輸出：

['Account', 'Value'] 
['ABC', 6] 
['DEF', 3] 
['GHI', 4] 
['JKL', 7] 

Answer 2

如果CSV有頭，我建議使用CSV.DictReader。隨着代言人，你可以：

with open('C:/Python27/testweight.csv', 'rb') as f: 
    reader = csv.DictReader(f) 
    for row in reader: 
     integer = int(row['column that contains an int']) 

希望這有助於！

Answer 3

你可以只遍歷所有的行如下：

import csv 

with open('C:/Python27/testweight.csv', 'rb') as f: 
    reader = csv.reader(f) 
    rows = [row for row in reader if row[1] > `s`] 

for index, cols in enumerate(rows[1:], 1): # Skip the header row 
    rows[index][1] = int(cols[1]) 

print rows 

這將顯示：

[['Account', 'Value'], ['ABC', 6], ['DEF', 3], ['GHI', 4], ['JKL', 7]]