分享8点超级有用的Python编程建议(推荐)

# 设置主目录
HOME_PATH = r'E:\ML\190615- PROJECT1'

# 读取数据
data = open(HOME_PATH+'/data/processed/test1.csv') 
data = pd.read_csv(data)
data.head()

import pysnooper

@pysnooper.snoop('./log/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({})