详解利用python读写csv，以及将csv数据写入数据库 - IT评测·应用市场-qidao123.com

csv_text = """姓名,年龄,性别
张三,25,男
李四,28,男
王五,22,男
六六,29,女
子柒,28,女"""
for line in csv_text.split("\n")[1::]:
item = line.split(",")
print("姓名：", item[0])
print("年龄：", item[1])
print("性别：", item[2])
print()

复制代码

import csv
with open("my_file.csv") as f:
csv_reader = csv.reader(f, delimiter=",")
for row in csv_reader:
print(row)

复制代码

import csv
with open("my_file.csv", "w", newline="") as f:
csv_writer = csv.writer(f, delimiter=",")
csv_writer.writerow(['姓名', '年龄', '性别'])
csv_writer.writerow(['张三', '25', '男'])
csv_writer.writerow(['李四', '28', '男'])
csv_writer.writerow(['王五', '22', '男'])
csv_writer.writerow(['六六', '29', '女'])
csv_writer.writerow(['子柒', '28', '女'])

复制代码

import pandas as pd
csv_data = pd.read_csv("my_file.csv")
print(csv_data)

复制代码

import pandas as pd
# 如果csv_data已经是DataFrame
csv_data.to_csv("my_file.csv", index=False)

复制代码

import pandas as pd
data_list = [
['姓名', '年龄', '性别'],
['张三', '25', '男'],
['李四', '28', '男'],
['王五', '22', '男'],
['六六', '29', '女'],
['子柒', '28', '女']
]
csv_data = pd.DataFrame(data_list[1::], columns=data_list[0])
csv_data.to_csv("my_file.csv", index=False)

复制代码

import pandas as pd
import pymysql
import os
import re
try:
conn = pymysql.connect(
host="数据库地址",
user="用户名",
password="密码",
database="数据库名"
)
cursor = conn.cursor()
print("数据库连接成功！")
except pymysql.MySQLError as e:
print(f"数据库连接失败：{e}")
raise
csv_file_path = "my_csv.csv"
df = pd.read_csv(csv_file_path)
df = df.where(pd.notnull(df), None)
table_name = re.sub(r'\W|^(?=\d)', '_', os.path.splitext(os.path.basename(csv_file_path))[0])
def create_table(cursor, table_name, df):
columns = df.columns
types = df.dtypes
sql = f"CREATE TABLE IF NOT EXISTS `{table_name}` (id INT AUTO_INCREMENT PRIMARY KEY, "
for col, dtype in zip(columns, types):
if "int" in str(dtype):
sql += f"`{col}` INT, "
elif "float" in str(dtype):
sql += f"`{col}` FLOAT, "
elif "datetime" in str(dtype):
sql += f"`{col}` DATETIME, "
else:
max_length = df[col].astype(str).map(len).max()
sql += f"`{col}` VARCHAR({max_length}), "
sql = sql.rstrip(", ") + ") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;"
try:
cursor.execute(sql)
print(f"表 `{table_name}` 创建成功！")
except pymysql.MySQLError as e:
print(f"创建表时出错：{e}")
cursor.close()
conn.close()
raise
create_table(cursor, table_name, df)
def insert_data(cursor, table_name, df):
cols = "`,`".join([str(i) for i in df.columns.tolist()])
placeholders = ','.join(['%s'] * len(df.columns))
sql = f"INSERT INTO `{table_name}` (`{cols}`) VALUES ({placeholders})"
data = df.values.tolist()
try:
cursor.executemany(sql, data)
conn.commit()
print(f"数据成功插入到表 `{table_name}` 中！")
except pymysql.MySQLError as e:
conn.rollback()
print(f"插入数据时出错：{e}")
cursor.close()
conn.close()
raise
insert_data(cursor, table_name, df)
cursor.close()
conn.close()

复制代码

import pymysql
import csv
source_conn = pymysql.connect(
host="源数据库地址",
user="用户名",
password="密码",
database="源数据库名"
)
source_cursor = source_conn.cursor()
source_cursor.execute("SHOW TABLES")
tables = source_cursor.fetchall()
for table in tables:
table_name = table[0]
source_cursor.execute(f"SELECT * FROM {table_name}")
rows = source_cursor.fetchall()
columns = [desc[0] for desc in source_cursor.description]
with open(f"{table_name}.csv", "w", newline="", encoding="utf-8") as file:
writer = csv.writer(file)
writer.writerow(columns)
writer.writerows(rows)
source_cursor.close()
source_conn.close()

复制代码

姓名	年岁	性别
张三	25	男
李四	28	男
王五	23	男
六六	36	女
子柒	34	女