将json中所有字段四舍五入保留n位小数

json中数据不规范，有时我们需要将数值(字符串类型的数值)统一保留多少位小数。

以下是我的代码，使用递归算法遍历json中所有的层。只要发现value值为浮点型或可转换成数值型的字符串则全部转换成浮点数；

具体代码如下：

class RoundJSON(object):

#data:需要处理的目标json，digit为保留多少位小数位默认保留4位

def round_data(self,data={},digit=4):#将data中的所有字段只要是数值则四舍五入,可以处理科学计数法    if(type(data)==type({})):        keys=data.keys()        if (len(keys) > 0 and type(keys)!=type(None)):            for key in keys:                value=data.get(key)                isnum=self.is_number(value)                if(isnum==True):                    value = self.roundUp(value, digit)                    data[key] = value                elif(type(value)==type({}) or type(value)==type([])):                    self.round_data(value, digit)    elif(type(data)==type([])):        for i in range(len(data)):            if (type(data[i]) == type({})):                keys = data[i].keys()                if(len(keys)>0 and type(keys)!=type(None)):                    for key in keys:                        value = data[i].get(key)                        if (self.is_number(value) == True):                            value = self.roundUp(value, digit)                            data[i][key] = value                        elif(type(value)==type({}) or type(value)==type([])):                            self.round_data(value, digit)            elif(type(data[i]) == type([]) and len(data[i])>0):                for value in data[i]:                    if (self.is_number(value) == True):                        value_new = self.roundUp(value, digit)                        data[i]=[value_new if x==value else x for x in data[i]]                    elif (type(value) == type({}) or type(value) == type([])):                        self.round_data(value, digit)            else:                if (self.is_number(data[i]) == True):                    value_new = self.roundUp(data[i], digit)                    data=[value_new if x==data[i] else x for x in data]                elif (type(data[i]) == type({}) or type(data[i]) == type([])):                    self.round_data(data[i], digit)    return data

def is_number(self,s):  #判断字符串s是否是数值    try:        float(s)        return True    except Exception as e:        pass    try:        unicodedata.numeric(s)        return True    except Exception as e:        pass    return False

def roundUp(self, value, digit):    flag = self.is_number(value)    if (flag == True and ‘e‘ not in str(value)): #排除科学计数法        result = str(value)        if (float(value) < 0):            result = result[1:]            if (result != ‘‘):                indexDec = result.find(‘.‘)                if (indexDec > 0):                    decimal = result[indexDec + 1:]                    decimalCount = len(decimal)                    if (decimalCount > digit):                        xiaoshu = result[indexDec + digit + 1]  # 第digit+1位小数                        if (int(xiaoshu) > 4):                            result = str(float(value) * -1 + pow(10, digit * -1))                            # 存在进位的可能，小数点会移位                            indexDec = result.find(‘.‘)                            result = result[:indexDec + digit + 1]                        else:                            result = result[:indexDec + digit + 1]                    else:                        lens = digit - len(result[indexDec:]) + 1                        for i in range(lens):                            result += ‘0‘            result = float(result) * -1            return result

原文地址：https://www.cnblogs.com/shuyichao/p/10450094.html