检索 csv 文件的内容作为列表

Question

将 csv 文件的内容作为列表检索的最佳和最优雅的方法是什么？请注意，国家、地区和人口等必填列将在下面的程序中自动识别。

with open ('data.csv','r') as infile:
    contents = infile.read().split(',')

with open ('data.csv','r') as infile:
    countries = [item.split(',')[contents.index('Country')] for item in infile]

with open ('data.csv','r') as infile:
    areas = [item.split(',')[contents.index('Area')] for item in infile]

with open ('data.csv','r') as infile:
    populations = [item.split(',')[contents.index('Population')] for item in infile]

print (countries)
print (areas)
print (populations)

上述程序有效，但正在寻找非常简短易读的程序。

更新： 为了防止在某些文件中不存在某些列（例如“国家”）时出现错误，可以通过以下方式改进程序：

countries = [item.split(',')[contents.index('Country')] for item in infile if 'Country' in contents]

如何使用 csv 模块完成？

Answer 1

对 CSV 文件使用 csv module：

import csv

countries = []
areas = []
populations = []

with open ('data.csv', newline='') as infile:
    reader = csv.DictReader(infile)
    for row in reader:
        countries.append(row['Country'])
        areas.append(row['Area'])
        populations.append(row['Population'])

DictReader() 类自动使用第一行标题作为文件其余部分的键。

或使用：

import csv

with open ('data.csv', newline='') as infile:
    reader = csv.reader(infile)
    next(reader, None)  # skip the header first
    countries, areas, populations = zip(*reader)

如果你只有 3 列，国家、地区和人口，按顺序排列。