Question

运行比较两个csv文件的python脚本后，剩下一个新的csv文件，该文件仅列出了新学生的电子邮件地址。（稍后将用于在我们的电子邮件系统中自动创建新用户）。

但是，我需要获取仅具有电子邮件地址的csv文件，并基于电子邮件地址中的信息，创建一个新的csv文件，该文件的标题为firstname，lastname，email，然后具有适当的数据用于每行。

示例：

原始csv（newemails.csv）

john.doe@mydomain.com
terry.jackson@mydomain.com
silly.sally@mydomain.com

新的CSV文件应如下所示：

firstname, lastname, email
John, Doe, john.doe@mydomain.com
Terry, Jackson, terry.jackson@mydomain.com
Silly, Sally, silly.sally@mydomain.com

这是我当前的代码，为我提供了newemails.csv文件

import csv
import os
import subprocess

def newemails():

for line in fileinput.input(r'C:\gamwork\currentstudents.csv', inplace=1):
    print(line.lower(), end='')


with open(r'C:\gamwork\previoususers.csv', 'r') as t1, 
open(r'C:\gamwork\currentstudents.csv', 'r') as t2:
    fileone = t1.readlines()
    filetwo = t2.readlines()

with open(r'C:\gamwork\newemails.csv', 'w') as outFile:
    for line in filetwo:
        if line not in fileone:
            outFile.write(line)

我真的不确定从这里开始怎么做，任何建议都将不胜感激！

Answer 1

您可以尝试以下操作：如果您的文件包含

john.doe@mydomain.com
terry.jackson@mydomain.com
silly.sally@mydomain.com

然后您可以执行以下操作：

with open('mydata.csv', 'r') as f, open('out.csv', 'w') as out_file:
    out_file.write('First name, last name, email\n')
    for line in f:
        names, email = line.split('@')[0], line
        first, last = names.split('.')
        new_line = f'{first}, {last}, {email}'
        out_file.write(new_line)


with open('out.csv', 'r') as out_file:
    print(out_file.read())

输出：

First name, last name, email
john, doe, john.doe@mydomain.com
terry, jackson, terry.jackson@mydomain.com
silly, sally, silly.sally@mydomain.com

Answer 2

使用pandas可以轻松实现请在下面找到一个示例。

import pandas as pd

df = pd.read_csv('test3.csv',  header=None, names=['Email'])
df['FirstName'] = [x.split('.')[0].title() for x in df['Email']]
df['LastName'] = [x.split('.')[1].split('@')[0].title() for x in df['Email']]
df = df.drop('Email', 1)
print(df)
df.to_csv('students.csv')

或其他解决方案是

import pandas as pd

def createFirstLastNames(row):
    firstLast = row['Email'].split('@')[0]
    firstName = firstLast.split('.')[0].title()
    lastName = firstLast.split('.')[1].title()
    return pd.Series({
        'FirstName' : firstName,
        'LastName' : lastName
    })

df = pd.read_csv('test3.csv',  header=None, names=['Email'])
df1 = df.merge(df.apply(lambda row: createFirstLastNames(row), axis=1), left_index=True, right_index=True)
df1 = df1.drop('Email', 1)
print(df1)
df1.to_csv('students.csv')

输出如下

FirstName LastName
John      Doe
Terry  Jackson
Silly    Sally

如何读取csv文件，以及如何基于csv中的数据添加标题和新列并输出新的csv

2 个答案: