从csv文件中读取每一列

Question

我想读取csv文件的每一列,并在将它们存储到表中之前进行一些修改.

我有一个csv文件:

"1";"testOne";"ValueOne"
"2";"testTwo";"ValueTwo"
"3";"testThree";"ValueThree"

在这里,我想读取第一个值"1",然后将其存储在变量中,并使用此值执行某些操作,并与其他值类似.但是目前我可以读取整个文件,但找不到连续访问各列的方法.

谢谢.

Answer 1

Python有一个内置的csv模块.

import csv
with open('some.csv', 'rb') as f:
    reader = csv.reader(f, delimiter=';')
    for row in reader:
        print row[0]

Answer 2

顶部的答案是灵活和pythonic,但如果你想要一些更紧凑和光滑的东西,一次从分隔数据(舒适地适合内存)检索整个列,你也可以尝试这样做:

c_reader = csv.reader(open('test.csv', 'r'), delimiter=';')

# say you want the second column, only...
col_2 = list(zip(*c_reader))[1] # keeping in mind that python is 0-indexed

# or if you want to come back for more later on, you can just do...
columns = list(zip(*c_reader))

比传统的pythonic更具传统性,但仍具有功能性感觉:

# just using a good old list comprehension
col_2 = [x[1] for x in c_reader]

# you could also get all the rows simply in this way
rows = [x for x in c_reader]
row_2 = rows[1]

现在出去与iterables成为一体!;-)