python for csv文件循環

Question

此代碼顯示csv文件的前兩行：

with open('myfile.csv', 'r') as f:
    for n, l in enumerate(f):
        if n > 1:
            break
        print l

如何將上面的代碼集成到下面的代碼？ （我正在尋找sendPackage為兩行）

with open(sys.argv[1]) as csvfile:
    reader = csv.DictReader(csvfile)
    for row in reader:
        sendPackage(row, job_id)

Answer 1

還有其他方法，但這正是您所要求的簡單答案：

with open(sys.argv[1]) as csvfile:
    reader = csv.DictReader(csvfile)
    for row_num, row in enumerate(reader):
        if row_num > 1:
            break
        sendPackage(row, job_id)

Answer 2

一種更整潔的方法是使用itertools.islice 。

import csv
import sys
from itertools import islice

def sendPackage(row, job_id):
    print('row {}: job {}'.format(row, job_id))

with open(sys.argv[1]) as csvfile:

    reader = csv.DictReader(csvfile)
    for row in islice(reader, 2):
        sendPackage(row, 1) # dummy value for job_id

該代碼最多需要reader包含2個元素。 如果少於2個元素，則在對其進行迭代后停止。