CSV文件導入到Python

Question

我想導入CSV文件到Python。我在這裏有兩個問題。

Q1。我的代碼是：

import csv 
with open('highfrequency2.csv') as csvfile: 
    freq=csv.reader(csvfile, delimiter=',') 
    for row in freq: 
    print(row[1],row[8]) 

但這裏有一個錯誤信息

IndexError：列表索引超出範圍

Q2。我的數據輸出看起來像

['WOSl.TQ', '02-Jan-14', '51:48.0', 'Quote', '', ''] 
['WOSl.TQ', '02-Jan-14', '51:48.0', 'Quote', '', ''] 
['WOSl.TQ', '02-Jan-14', '51:48.0', 'Quote', '', ''] 
['WOSl.TQ', '02-Jan-14', '51:48.0', 'Quote', '', ''] 
['WOSl.TQ', '02-Jan-14', '51:48.0', 'Quote', '', ''] 
..... 
.... 

我必須使用「R」或「RB」功能在閱讀文件？

我想查看CSV文件的第2行和第8行。

Answer 1

您的排有6個元素，您正在嘗試打印第2個和第9個。好吧，後者不存在，因此列表索引超出範圍（索引從0開始）。

Answer 2

如果你只是想行2-8，讀者對象使用itertools.islice：

import csv 
from itertools import islice, izip 

with open('highfrequency2.csv') as csvfile: 
    freq = csv.reader(csvfile) 
    # create islice object 
    interest = islice(freq, 1, 8, None)) 
    # iterate over islice object getting row at a time 
    for row in interest: 
     print(row) 

如果你只是想這兩個特定的行使用6的step：

import csv 
from itertools import islice, izip 

with open('highfrequency2.csv') as csvfile: 
    freq = csv.reader(csvfile) 
    interest = islice(freq, 1, 8, 6)) 
    for row in interest: 
     print(row) 

或撥打接下來跳過第一行之後的讀者對象：

import csv 

with open('highfrequency2.csv') as csvfile: 
    freq = csv.reader(csvfile) 
    next(freq) 
    # create generator expression 
    interest = (next(freq) for _ in range(7)) 
    for row in interest: 
     print(row) 

或者我們枚舉：

import csv 

with open('highfrequency2.csv') as csvfile: 
    freq = csv.reader(csvfile) 
    interest = (row for ind, row in enumerate(freq) if ind in {1,7}) 
    for row in interest: 
     print(row)