实例网站
https://www.programcreek.com/python/
读写文件
写文件
#!/usr/bin/env python3
with open('test.txt', 'w') as f:
f.write('hello\n')
f.write('python')
读文件
#!/usr/bin/env python3
with open('test.txt', 'r') as f:
for l in f.readlines():
print(l, end='')遍历文件夹下的所有文件
#!/usr/bin/env python3
import pathlib
import pprint
pprint.pprint(list(pathlib.Path().rglob("*")))遍历所有文件，gbk转码为utf-8
#!/usr/bin/env python3
import pathlib
for path in pathlib.Path().rglob("*"):
file_name = str(path.resolve())
if not file_name.endswith(".h") or not file_name.endswith("*.cpp"):
continue
f1 = open(file_name, "rb")
content = str(f1.read(), "gbk")
f1.close()
f2 = open(file_name, "wb")
f2.write(content.encode("utf8"))
f2.close()
print(file_name)日期时间文本转为时间戳
import datetime
datetimestr = "2021-01-01 00:00:00"
dt = datetime.datetime.strptime(datetimestr, "%Y-%m-%d %H:%M:%S")
timestamp = dt.replace(tzinfo=datetime.timezone.utc).timestamp()RESTful 服务器
以下代码使用python标准库，推荐使用更好用的Flask-RESTful。
#!/usr/bin/env python3
from http import *
from http.server import *
from urllib.parse import urlparse
import json
class HTTPRequestHandler(BaseHTTPRequestHandler):
def do_POST(self):
url = urlparse(self.path)
path = url.path
if path == "/test":
rep = json.dumps({"key1": "test"})
self.send_response(HTTPStatus.OK)
self.send_header("Content-Type", "application/json")
self.send_header("Content-Length", str(len(rep)))
self.end_headers()
self.wfile.write(rep)
server_address = ("0.0.0.0", 8080)
print("Serving HTTP on " + str(server_address))
httpd = HTTPServer(server_address, HTTPRequestHandler)
httpd.serve_forever()使用SQLite数据库
import sqlite3
connection = sqlite3.connect("test.db")
connection.row_factory = sqlite3.Row
cursor = connection.cursor
# SQL语句
sql = "..."
# 执行SQL语句，如果是修改数据库内容，必须调用commit
try:
cursor.execute(sql)
connection.commit()
except BaseException as e:
print("error: " + str(e))
# 执行查询语句时，获取单个记录
try:
cursor.execute(sql)
row = cursor.fetchone()
if row:
keys = row.keys() # 所有字段名
vals = list(row) # 所有字段值
data = dict(zip(keys, vals)) # 构成一个字典
except BaseException as e:
print("error: " + str(e))
# 执行查询语句时，获取所有记录
try:
for row in cursor.execute(sql):
keys = row.keys() # 所有字段名
vals = list(row) # 所有字段值
data = dict(zip(keys, vals)) # 构成一个字典
except BaseException as e:
print("error: " + str(e))自动关机
Windows
在指定时间到达时关机：
import os
import time
import datetime
# 晚上9点
shutdown_time = datetime.time(21, 0, 0)
print('System will shutdown at " + str(shutdown_time))
while True:
current_time = datetime.datetime.now().time()
if current_time >= shutdown_time:
print('Shutdown now...')
os.system('shutdown /s /t 5') # 5秒后关机
break
else:
time.sleep(1)指定进程退出后关机：
import psutil
import time
import os
def proc_exist(process_name):
pids = psutil.pids()
for pid in pids:
try:
if psutil.Process(pid).name() == process_name:
return True
except:
continue
return False
while True:
if proc_exist('vcpkg.exe'):
print('vcpkg.exe is running')
time.sleep(5)
else:
print('shutdown now')
os.system('shutdown /s /t 5')
break处理命令行参数
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import argparse
parser = argparse.ArgumentParser(description="程序描述")
# 互斥组（组内的各参数不能同时使用）
group = parser.add_mutually_exclusive_group()
group.add_argument("-a", "--aaa", help="a参数描述", action="store_true")
group.add_argument("-b", "--bbb", help="b参数描述", type=int)
group.add_argument("-c", "--ccc", help="c参数描述")
args = parser.parse_args()
if args.aaa:
pass
elif args.bbb:
pass
elif arg.ccc:
pass
else:
parser.print_help()The Python Standard Library » Generic Operating System Services » argparse — Parser for command-line options, arguments and sub-commands
使用 psutil 查看进程信息
安装
sudo dnf install gcc python3-devel
pip install psutil使用
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import psutil
# 遍历所有进程，输出进程ID，CPU占比，内存，进程名称
for pid in psutil.pids():
p = psutil.Process(pid)
print("{},{},{},{}".format(
p.pid, p.cpu_percent(), p.memory_info().rss, p.name()));