测开之路八十五：python处理csv文件

写入csv文件

一：写入字典

二：写入普通数据

读取：

第一种：普通读取

第二种：读取csv并用namedtuple映射列名，类似于使用类的实例

第三种：字典形式

import csv
from collections import namedtuple


def csv_write_dict():
    """ 写入字典 """
    header = ["_id", "column1", "column2", "column3"]
    rows = [
        {"_id": 1, "column1": "a1", "column2": "b1", "column3": "c1"},
        dict(_id=2, column1="a2", column2="b2", column3="c2")
    ]
    with open("data.csv", "w", encoding="utf8", newline="") as f:
        writer = csv.DictWriter(f, header)
        writer.writeheader()
        writer.writerows(rows)


def csv_write():
    """ 写入csv文件 """
    header = ["id", "column1", "column2", "column3"]
    rows = [
        (1, "a1", "b1", "c1"),
        (2, "a2", "b2", "c2")
    ]
    with open('data.csv', "w", encoding='utf8', newline='') as f:
        write = csv.writer(f)
        write.writerow(header)  # 写一行，第一行
        write.writerows(rows)  # 写多行，内容


def csv_read():
    """ 普通读取csv """
    with open('data.csv', encoding='utf8') as f:
        reader = csv.reader(f)  # 加载csv
        headers = next(reader)  # 第一行，即表头
        print(headers)
        for row in reader:
            print(row)  # 取出来是list
            print(f'id: {row[0]}, column1: {row[1]}, column2: {row[2]}, column3: {row[3]}')


def csv_read_by_namedtuple():
    """ 读取csv并用namedtuple映射列名 """
    with open('data.csv', encoding='utf8') as f:
        reader = csv.reader(f)  # 加载csv
        headers = next(reader)  # 第一行，即表头
        Row = namedtuple('Row', headers)
        for r in reader:
            row = Row(*r)
            print(row)
            print(f'{row.id}--{row.column1}--{row.column2}--{row.column3}')


def csv_read_by_dict():
    """ 读取csv为字典形式 """
    with open('data.csv', encoding='utf8') as f:
        reader = csv.DictReader(f)  # 以字典形式加载csv
        for row in reader:
            print(row)
            print(f'id:{row["id"]}--column1:{row.get("column1")}--'
                  f'column12:{row.get("column2", "未获取到值")}--'
                  f'column3:{row.get("column3")}')


if __name__ == '__main__':
    csv_write()
    csv_write_dict()
    csv_read()
    csv_read_by_namedtuple()
    csv_read_by_dict()