CSV文件的标题栏怎么写？

Question

def write_vt(d, filename):     f = open(filename, 'w')我应该以写入模式打开新文件，然后在标题列中写入，然后使用 for 循环将数据字符串添加到文件中。但我就是不知道如何做到这一点......原始文件名为votes.csv.

Answer 1

有很多方法可以做到这一点，具体取决于您的数据和您愿意使用的工具：

a) 用列表和标题逐行写入 CSV

import csv

data_list = [

    ["Russia", "Moscow", "Russian"],

    ["US", "Washington, D.C.", "English"],

    ["Colombia", "Bogotá", "Spanish"]

]

header = ["col1", "col2", "col3"]

def write_csv_from_lists(data, header, filename):

    with open(filename, "w") as csv_file:

        csv_writer = csv.writer(csv_file)

        csv_writer.writerow(header) # write header

        for row in data:

            csv_writer.writerow(row) # write each row

write_csv_from_lists(data_list, header, "file1.csv")

文件1.csv

col1,col2,col3

Russia,Moscow,Russian

US,"Washington, D.C.",English

Colombia,Bogotá,Spanish

b) 用字典和标题逐行写入 CSV

import csv

data_dict = [

    {"col1": "Russia", "col2": "Moscow", "col3": "Russian"},

    {"col1": "US", "col2": "Washington, D.C.", "col3": "English"},

    {"col1": "Colombia", "col2": "Bogotá", "col3": "Spanish"}

]

header = ["col1", "col2", "col3"]

def write_csv_from_dicts(data, header, filename):

    with open(filename, "w") as csv_file:

        dict_writer = csv.DictWriter(csv_file, fieldnames=header)

        dict_writer.writeheader() # write header

        for row in data:

            dict_writer.writerow(row) # write each row

write_csv_from_dicts(data_dict, header, "file2.csv")

文件2.csv

col1,col2,col3

Russia,Moscow,Russian

US,"Washington, D.C.",English

Colombia,Bogotá,Spanish

c) 用 Pandas 编写 CSV

import pandas as pd

data_dict = [

    {"col1": "Russia", "col2": "Moscow", "col3": "Russian"},

    {"col1": "US", "col2": "Washington, D.C.", "col3": "English"},

    {"col1": "Colombia", "col2": "Bogotá", "col3": "Spanish"}

]

def write_csv_pandas(data, filename):

    pd.DataFrame(data).to_csv(filename, index=False)

write_csv_pandas(data_dict, "file3.csv")

文件3.csv

col1,col2,col3

Russia,Moscow,Russian

US,"Washington, D.C.",English

Colombia,Bogotá,Spanish

Answer 2

您可以使用它来添加标题：

header = "col1,col2,col3"

with open('file.csv','w') as my_csv:

    my_csv.write(header+'\n')

关于用数据填充 CSV，这将取决于您将用作源的原始数据。