utils.py

# -*- coding: utf-8 -*-

import io
import six
import time
import random


def to_text(value, encoding='utf-8'):
    """将 value 转为 unicode，默认编码 utf-8

    :param value: 待转换的值
    :param encoding: 编码
    """
    if not value:
        return ''
    if isinstance(value, six.text_type):
        return value
    if isinstance(value, six.binary_type):
        return value.decode(encoding)
    return six.text_type(value)


def to_binary(value, encoding='utf-8'):
    """将 values 转为 bytes，默认编码 utf-8

    :param value: 待转换的值
    :param encoding: 编码
    """
    if not value:
        return b''
    if isinstance(value, six.binary_type):
        return value
    if isinstance(value, six.text_type):
        return value.encode(encoding)

    if six.PY3:
        return six.binary_type(str(value), encoding)  # For Python 3
    return six.binary_type(value)


def disable_urllib3_warning():
    """
    https://urllib3.readthedocs.org/en/latest/security.html#insecurerequestwarning
    InsecurePlatformWarning 警告的临时解决方案
    """
    try:
        import requests.packages.urllib3
        requests.packages.urllib3.disable_warnings()
    except Exception:
        pass


def generate_timestamp():
    """生成 timestamp
    :return: timestamp string
    """
    return int(time.time())


def generate_nonce():
    """生成 nonce
    :return: nonce string
    """
    return random.randrange(1000000000, 2000000000)


def convert_ext_to_mime(extension):
    """将扩展名转换为 MIME 格式
    :return: mime string
    """
    table = {
        'jpg': 'image/jpeg',
        'jpeg': 'image/jpeg',
        'amr': 'audio/amr',
        'mp3': 'audio/mpeg',
        'mp4': 'video/mp4',
    }

    if extension in table:
        return table[extension]
    raise ValueError("Invalid extension in MIME table")


def is_allowed_extension(extension, type='upload_media'):
    """检查扩展名是否是可以上传到服务器
    :return: True if ok
    """
    table = ('jpg', 'jpeg', 'amr', 'mp3', 'mp4')

    if extension in table:
        return True
    return False