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 datadef 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
将json中所有字段四舍五入保留n位小数
原文地址：https://www.cnblogs.com/shuyichao/p/10450094.html