1

我有这个代码：

from flask import Flask, flash, redirect, render_template, request, session, abort
import os
import json
from urllib.request import urlopen

tmpl_dir = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'templates')
app = Flask(__name__, template_folder=tmpl_dir)

def getExchangeRates():
    rates = []
    response = urlopen('https://data.fixer.io/api/latest?access_key=my_key')
    data = response.read()
    rdata = json.loads(data, parse_float=float)

    rates.append( rdata['rates']['USD'] )
    rates.append( rdata['rates']['GBP'] )
    rates.append( rdata['rates']['HKD'] )
    rates.append( rdata['rates']['AUD'] )
    return rates

@app.route("/")
def index():
    rates = getExchangeRates()
    return render_template('test.html',**locals())      

@app.route("/hello")
def hello():
    return "Hello World!"

但它给了我这个：

Traceback (most recent call last):
File "/home/kristian/.virtualenvs/usio_flask/lib/python3.4/site-packages/flask/app.py", line 2292, in wsgi_app
response = self.full_dispatch_request()
File "/home/kristian/.virtualenvs/usio_flask/lib/python3.4/site-packages/flask/app.py", line 1815, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/home/kristian/.virtualenvs/usio_flask/lib/python3.4/site-packages/flask/app.py", line 1718, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/home/kristian/.virtualenvs/usio_flask/lib/python3.4/site-packages/flask/_compat.py", line 35, in reraise
raise value
File "/home/kristian/.virtualenvs/usio_flask/lib/python3.4/site-packages/flask/app.py", line 1813, in full_dispatch_request
rv = self.dispatch_request()
File "/home/kristian/.virtualenvs/usio_flask/lib/python3.4/site-packages/flask/app.py", line 1799, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "app/app.py", line 23, in index
rates = getExchangeRates()
File "app/app.py", line 13, in getExchangeRates
rdata = json.loads(data, parse_float=float)
File "/usr/lib/python3.4/json/__init__.py", line 312, in loads
s.__class__.__name__))
TypeError: the JSON object must be str, not 'bytes'

违规行是这一行：

rdata = json.loads(data, parse_float=float)

我只是想从fixer.ioAPI 获得一些费率，有什么想法吗？

如果name == " main ": app.run()

4

1 回答 1

3

[Python 3.Docs]：json。加载（s, *, encoding=None, cls=None, object_hook=None, parse_float=None, parse_int=None, parse_constant=None, object_pairs_hook=None, **kw）状态：

使用此转换表将s（包含 JSON 文档的str、bytes或bytearray实例）反序列化为 Python 对象。

urllib.request.urlopen返回一个http.client.HTTPResponse对象。

根据[Python 3.Docs]：http.client - HTTPResponse。阅读（[amt]）：

读取并返回响应正文，或直到下一个amt bytes。

因此，为了完成这项工作，您必须将字节转换为str
（通过[Python 3.Docs]: bytes.decode ( encoding ="utf-8", errors="strict" )）：

rdata = json.loads(data.decode(), parse_float=float)

注意：

  • 从Python 3. 6开始，json.loads也能够处理字节

关于您的另一个错误，我记得（因为我曾经使用过Flask）如果HTTP状态代码为200（OK ），则Response对象只有一个json方法。但我不确定它是否与我们正在讨论的对象相同，因为我使用的是requests模块。

于 2018-08-15T17:16:38.110 回答