我的解决方案(我认为不那么冗长):

def default(o):
    if type(o) is datetime.date or type(o) is datetime.datetime:
        return o.isoformat()

def jsondumps(o):
    return json.dumps(o, default=default)

然后使用jsondumps而不是json.dumps。它将打印:

>>> jsondumps({'today': datetime.date.today()})
'{"today": "2013-07-30"}'

如果你想，以后你可以添加其他特殊情况，通过一个简单的默认方法。例子:

def default(o):
    if type(o) is datetime.date or type(o) is datetime.datetime:
        return o.isoformat()
    if type(o) is decimal.Decimal:
        return float(o)

您应该在.datetime.now()方法上应用.strftime()方法，使其成为一个可序列化的方法。

这里有一个例子:

from datetime import datetime

time_dict = {'time': datetime.now().strftime('%Y-%m-%dT%H:%M:%S')}
sample_dict = {'a': 1, 'b': 2}
sample_dict.update(time_dict)
sample_dict

输出:

Out[0]: {'a': 1, 'b': 2, 'time': '2017-10-31T15:16:30'}

(更新):

在Python3.7及以后版本中，你可以简单地使用.isoformat()方法:

from datetime import datetime

datetime.now().isoformat()

我的解决方案(我认为不那么冗长):

def default(o):
    if type(o) is datetime.date or type(o) is datetime.datetime:
        return o.isoformat()

def jsondumps(o):
    return json.dumps(o, default=default)

然后使用jsondumps而不是json.dumps。它将打印:

>>> jsondumps({'today': datetime.date.today()})
'{"today": "2013-07-30"}'

如果你想，以后你可以添加其他特殊情况，通过一个简单的默认方法。例子:

def default(o):
    if type(o) is datetime.date or type(o) is datetime.datetime:
        return o.isoformat()
    if type(o) is decimal.Decimal:
        return float(o)

这是我的完整的解决方案转换datetime JSON和回来..

import calendar, datetime, json

def outputJSON(obj):
    """Default JSON serializer."""

    if isinstance(obj, datetime.datetime):
        if obj.utcoffset() is not None:
            obj = obj - obj.utcoffset()

        return obj.strftime('%Y-%m-%d %H:%M:%S.%f')
    return str(obj)

def inputJSON(obj):
    newDic = {}

    for key in obj:
        try:
            if float(key) == int(float(key)):
                newKey = int(key)
            else:
                newKey = float(key)

            newDic[newKey] = obj[key]
            continue
        except ValueError:
            pass

        try:
            newDic[str(key)] = datetime.datetime.strptime(obj[key], '%Y-%m-%d %H:%M:%S.%f')
            continue
        except TypeError:
            pass

        newDic[str(key)] = obj[key]

    return newDic

x = {'Date': datetime.datetime.utcnow(), 34: 89.9, 12.3: 90, 45: 67, 'Extra': 6}

print x

with open('my_dict.json', 'w') as fp:
    json.dump(x, fp, default=outputJSON)

with open('my_dict.json') as f:
    my_dict = json.load(f, object_hook=inputJSON)

print my_dict

输出

{'Date': datetime.datetime(2013, 11, 8, 2, 30, 56, 479727), 34: 89.9, 45: 67, 12.3: 90, 'Extra': 6}
{'Date': datetime.datetime(2013, 11, 8, 2, 30, 56, 479727), 34: 89.9, 45: 67, 12.3: 90, 'Extra': 6}

JSON文件

{"Date": "2013-11-08 02:30:56.479727", "34": 89.9, "45": 67, "12.3": 90, "Extra": 6}

这使我能够导入和导出字符串，int，浮点和datetime对象。 扩展到其他类型应该不难。

通常有几种方法来序列化日期时间，比如:

ISO字符串，短，可以包含时区信息，例如@jgbarah的答案 时间戳(时区数据丢失)，例如@JayTaylor的答案 属性字典(包括时区)。

如果您同意最后一种方法，json_tricks包将处理日期、时间和日期时间(包括时区)。

from datetime import datetime
from json_tricks import dumps
foo = {'title': 'String', 'datetime': datetime(2012, 8, 8, 21, 46, 24, 862000)}
dumps(foo)

这使:

{"title": "String", "datetime": {"__datetime__": null, "year": 2012, "month": 8, "day": 8, "hour": 21, "minute": 46, "second": 24, "microsecond": 862000}}

所以你要做的就是

`pip install json_tricks`

然后导入从json_tricks而不是json。

不将其存储为单个字符串、int型或float型的优势体现在解码时:如果你遇到的只是字符串，特别是int型或float型，你需要了解一些关于数据的信息，以知道它是否是一个datetime。作为dict，您可以存储元数据，以便自动解码，这就是json_tricks为您做的。它也很容易为人类编辑。

免责声明:这是我做的。因为我也有同样的问题。

Another approach is to adopt a concept from FEEL (the Friendly Enough Expression Language) defined in DMN (Decision Model Notation) - namely @strings. Any string starting with @" and ending with " is decoded separately with FEEL decoding. Of course the sender and the receiver have to agree to this convention, but ... the code below lets you encode lots of other things as well as dates, times, date/times, timedeltas. You can encode year/month durations and ranges (so long as you except a 4 element tuple of chr, expr, expr, chr as being a good representation of a range - where the two chrs are open/close brackets). So, @"P4Y2M" is a duration of 4 years and 2 months. @"P2DT5H" is a timedelta of 2 days and 4 hours, @"(2021-01-02 .. 2021-12-31)" is a year range.

下面的代码可用于序列化和反序列化@strings。

import datetime
import pySFeel

parser = pySFeel.SFeelParser()


def convertAtString(thisString):
    # Convert an @string
    (status, newValue) = parser.sFeelParse(thisString[2:-1])
    if 'errors' in status:
        return thisString
    else:
        return newValue


def convertIn(newValue):
    if isinstance(newValue, dict):
        for key in newValue:
            if isinstance(newValue[key], int):
                newValue[key] = float(newValue[key])
            elif isinstance(newValue[key], str) and (newValue[key][0:2] == '@"') and (newValue[key][-1] == '"'):
                newValue[key] = convertAtString(newValue[key])
            elif isinstance(newValue[key], dict) or isinstance(newValue[key], list):
                newValue[key] = convertIn(newValue[key])
    elif isinstance(newValue, list):
        for i in range(len(newValue)):
            if isinstance(newValue[i], int):
                newValue[i] = float(newValue[i])
            elif isinstance(newValue[i], str) and (newValue[i][0:2] == '@"') and (newValue[i][-1] == '"'):
                newValue[i] = convertAtString(newValue[i])
            elif isinstance(newValue[i], dict) or isinstance(newValue[i], list):
                newValue[i] = convertIn(newValue[i])
    elif isinstance(newValue, str) and (newValue[0:2] == '@"') and (newValue[-1] == '"'):
        newValue = convertAtString(newValue)
    return newValue


  def convertOut(thisValue):
      if isinstance(thisValue, datetime.date):
          return '@"' + thisValue.isoformat() + '"'
      elif isinstance(thisValue, datetime.datetime):
          return '@"' + thisValue.isoformat(sep='T') + '"'
      elif isinstance(thisValue, datetime.time):
          return '@"' + thisValue.isoformat() + '"'
      elif isinstance(thisValue, datetime.timedelta):
          sign = ''
          duration = thisValue.total_seconds()
          if duration < 0:
              duration = -duration
              sign = '-'
          secs = duration % 60
          duration = int(duration / 60)
          mins = duration % 60
          duration = int(duration / 60)
          hours = duration % 24
          days = int(duration / 24)
          return '@"%sP%dDT%dH%dM%fS"' % (sign, days, hours, mins, secs)
      elif isinstance(thisValue, bool):
          return thisValue:
      elif thisValue is None:
          return thisValue:
      elif isinstance(thisValue, int):
          sign = ''
          if thisValue < 0:
              thisValue = -thisValue
              sign = '-'
          years = int(thisValue / 12)
          months = (thisValue % 12)
          return '@"%sP%dY%dM"' % (sign, years, months)
      elif isinstance(thisValue, tuple) and (len(thisValue) == 4):
          (lowEnd, lowVal, highVal, highEnd) = thisValue
          return '@"' + lowEnd + str(lowVal) + ' .. ' + str(highVal) + highEnd
      elif thisValue is None:
          return 'null'
      elif isinstance(thisValue, dict):
          for item in thisValue:
              thisValue[item] = convertOut(thisValue[item])
          return thisValue
      elif isinstance(thisValue, list):
          for i in range(len(thisValue)):
              thisValue[i] = convertOut(thisValue[i])
          return thisValue
      else:
          return thisValue