14csv文件操作

 

import csv
'''
csv文本操作,增删改查都需要遍历列表进行判断操作，如果要删除某行，可以del row[1] ,del用于删除列表元素。
def read_csv(file_path):
    """
    读取CSV文件内容
    """
    with open(file_path, 'r') as file:
        reader = csv.reader(file)
        for row in reader:
            print(row)

def write_csv(file_path, data):
    """
    写入数据到CSV文件
    """
    with open(file_path, 'w', newline='') as file:
        writer = csv.writer(file)
        writer.writerows(data)

def add_row(file_path, row_data):
    """
    添加一行数据到CSV文件
    """
    with open(file_path, 'a', newline='') as file:
        writer = csv.writer(file)
        writer.writerow(row_data)

def update_row(file_path, row_index, new_row_data):
    """
    更新CSV文件中的一行数据
    """
    rows = []
    with open(file_path, 'r') as file:
        reader = csv.reader(file)
        for row in reader:
            rows.append(row)

    if row_index < len(rows):
        rows[row_index] = new_row_data

    with open(file_path, 'w', newline='') as file:
        writer = csv.writer(file)
        writer.writerows(rows)

def delete_row(file_path, row_index):
    """
    删除CSV文件中的一行数据
    """
    rows = []
    with open(file_path, 'r') as file:
        reader = csv.reader(file)
        for row in reader:
            rows.append(row)

    if row_index < len(rows):
        del rows[row_index]

    with open(file_path, 'w', newline='') as file:
        writer = csv.writer(file)
        writer.writerows(rows)
'''

# 往csv文件写入内容
def write_csv():
    with open('./annex/data.csv', 'a', encoding='utf-8', newline='') as file:
        writer = csv.writer(file)
        writer.writerow(['1', '李四', '19'])
        writer.writerow(['2', '张三', '17'])
        writer.writerow(['3', '李贵', '26'])


# 从csv文件中读取内容
def read_csv():
    with open('./annex/data.csv', 'r', encoding='utf-8', newline='') as file:
        reader = csv.reader(file)
        print("reader",type(reader))
        for row in reader:
            print(row)
            print(type(row))


def write_csvs():
    with open('./annex/data.csv', 'w', encoding='utf-8', newline='') as file:
        writer = csv.writer(file)
        data=[['1','小明','语文','69'],[2,'小红','英语','86'],[3,'小东','数学','99']]
        writer.writerows(data)

# 获取csv文件有多少列
def get_csv_column_count():
    file_path = './annex/data.csv'
    with open(file_path,'r',encoding='utf-8') as file:
        reader = csv.reader(file)
        first_row= next(reader)
        column_count = len(first_row)
        print(column_count)

if __name__ == '__main__':
    # write_csvs()
    read_csv()