CSV文件导入到Python

Question

我想导入CSV文件到Python。我在这里有两个问题。

Q1。我的代码是：

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

但这里有一个错误信息

IndexError：列表索引超出范围

Q2。我的数据输出看起来像

['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', '', ''] 
..... 
.... 

我必须使用“R”或“RB”功能在阅读文件？

我想查看CSV文件的第2行和第8行。

Answer 1

您的排有6个元素，您正在尝试打印第2个和第9个。好吧，后者不存在，因此列表索引超出范围（索引从0开始）。

Answer 2

如果你只是想行2-8，读者对象使用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) 

如果你只是想这两个特定的行使用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) 

或拨打接下来跳过第一行之后的读者对象：

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) 

或者我们枚举：

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)