python学习随笔

1、读取/写入json文件

import jsondef format_json(json_file, dics):with open(json_file, 'w', encoding='utf-8') as f:json.dump(dics, f, indent=4, ensure_ascii=False)def load_json(json_file):try:with open(json_file, 'r', encoding='utf-8') as f:return json.load(f)except FileNotFoundError:print(f"{json_file} is not found.")return Noneif __name__ == '__main__':dics = {'name': 'zhangsan'}json_file = 'test.json'format_json(json_file, dics)dic1 = load_json(json_file)if dic1 is not None:print(dic1)

2、多线程

def worker(delay=1):time.sleep(delay)print(f'sleep1=====>>>{delay}')


if __name__ == '__main__':# threadthread1 = threading.Thread(target=worker, args=(1,))thread2 = threading.Thread(target=worker, args=(2,))thread1.start()thread2.start()thread1.join()thread2.join()

 

3、lambda表达式（最基础的用法）

x = lambda a, b, c : a * b + c
print(x(2, 4, 5))##########
13

4、列表推导式和生成器表达式

# 获取当前目录下的所有bin文件，且以'_'开头
import os
bin_files = [bin for bin in os.listdir('.') if bin.endswith('.bin') if bin.startswith('_')]
print(bin_files)

　　生成器表达式得到的是元组

5、读取或写入bin/npy文件

def create_npy(shape1=(1,3,12,12), dtype='float32', _min=-5, _max=5):# 生成数据data = np.random.rand(*shape1) * (_max - _min) + _mindata = data.astype(dtype)# 保存数据np.save("xxx1.npy", data)# 读取npy数据npy_data = np.load("xxx1.npy")print(npy_data.shape)print(npy_data.dtype)# 保存bin数据npy_data.astype(dtype).tofile("xxx1.bin")# 读取bin文件bin_data = np.fromfile("xxx1.bin", dtype=dtype)print(bin_data)

6、pytest魔法文件

conftest.py

import pytestdef pytest_addoption(parser):parser.addoption("--quant", action="True", help="run with quant.")def str_to_bool(s):if s.lower() == 'flase':return Falseelif s.lower() = 'true':return True@pytest.fixture
def quant_flag(request):return str_to_bool(request.config.getoption("--quant"))