Python机器学习项目实战：8个提升代码质量与效率的实用建议

# 设置主目录
HOME_PATH = r'E:ML90615- PROJECT1'
# 读取数据
data = open(HOME_PATH+'/data/processed/test1.csv')
data = pd.read_csv(data)
data.head()

import pysnooper
@pysnooper.snoop('./file.log')
def number_to_bits(number):
 if number:
 bits = []
 while number:
 number, remainder = divmod(number, 2)
 bits.insert(0, remainder)
 return bits
 else:
 return [0]
number_to_bits(6)

def add(a, b):
 if isinstance(a, int) and isinstance(b, int):
 return a+b
 else:
 return '参数类型错误'
print(add(1, 2))
print(add(1, 'a'))

from requests.exceptions import RequestException
def save_website_title(url, filename):
 try:
 resp = requests.get(url)
 except RequestException as e:
 print(f'save failed: unable to get page content: {e}')
 return False
# 这段正则操作本身就是不应该抛出异常的，所以我们没必要使用 try 语句块
# 假如 group 被误打成了 grop 也没关系，程序马上就会通过 AttributeError 来
# 告诉我们。
obj = re.search(r'<title>(.*)</title>', resp.text)
if not obj:
 print('save failed: title tag not found in page content')
 return False
title = obj.group(1)
try: with open(filename, 'w') as fp:
 fp.write(title)
except IOError as e:
 print(f'save failed: unable to write to file {filename}: {e}')
 return False
else:
 return True

class raise_api_error:
"""captures specified exception and raise ApiErrorCode instead
:raises: AttributeError if code_name is not valid
"""
def __init__(self, captures, code_name):
 self.captures = captures
 self.code = getattr(error_codes, code_name)
def __enter__(self):
 # 该方法将在进入上下文时调用
 return self
def __exit__(self, exc_type, exc_val, exc_tb):
 # 该方法将在退出上下文时调用
 # exc_type, exc_val, exc_tb 分别表示该上下文内抛出的
 # 异常类型、异常值、错误栈
 if exc_type is None:
 return False
 if exc_type == self.captures:
 raise self.code from exc_val
 return False

def upload_avatar(request):
 """用户上传新头像"""
with raise_api_error(KeyError, 'AVATAR_FILE_NOT_PROVIDED'):
 avatar_file = request.FILES['avatar']
with raise_api_error(ResizeAvatarError, 'AVATAR_FILE_INVALID'),
 raise_api_error(FileTooLargeError, 'AVATAR_FILE_TOO_LARGE'):
 resized_avatar_file = resize_avatar(avatar_file)
with raise_api_error(Exception, 'INTERNAL_SERVER_ERROR'):
 request.user.avatar = resized_avatar_file
 request.user.save()
return HttpResponse({})