vnpy/vn.trader/vtFunction.py

# encoding: UTF-8

"""
包含一些开放中常用的函数
"""

import decimal
import json

MAX_NUMBER = 10000000000000
MAX_DECIMAL = 4

#----------------------------------------------------------------------
def safeUnicode(value):
    """检查接口数据潜在的错误，保证转化为的字符串正确"""
    # 检查是数字接近0时会出现的浮点数上限
    if type(value) is int or type(value) is float:
        if value > MAX_NUMBER:
            value = 0
    
    # 检查防止小数点位过多
    if type(value) is float:
        d = decimal.Decimal(str(value))
        if abs(d.as_tuple().exponent) > MAX_DECIMAL:
            value = round(value, ndigits=MAX_DECIMAL)
    
    return unicode(value)

#----------------------------------------------------------------------
def loadMongoSetting():
    """载入MongoDB数据库的配置"""
    try:
        f = file("VT_setting.json")
        setting = json.load(f)
        host = setting['mongoHost']
        port = setting['mongoPort']
    except:
        host = 'localhost'
        port = 27017
        
    return host, port