小编use*_*937的帖子

我有一个列出值的列表,我得到的值之一是'nan'

countries= [nan, 'USA', 'UK', 'France']

我试图删除它,但我每次都会收到错误

cleanedList = [x for x in countries if (math.isnan(x) == True)]
TypeError: a float is required

当我尝试这个时:

cleanedList = cities[np.logical_not(np.isnan(countries))]
cleanedList = cities[~np.isnan(countries)]

TypeError: ufunc 'isnan' not supported for the input types, and the inputs could not be safely coerced to any supported types according to the casting rule ''safe''

我在我的图表中显示了超过40个项目.我只有10种颜色反复显示在图表上.如何生成更多颜色.

plt.pie(f,labels=labels,autopct='%1.1f%%', startangle=90,shadow=True)

我应该添加"color = colors",其中颜色是无限生成的？

我正在努力在 python 中聚合 Json 文件 我使用列表理解来获取所有负责机构

import pandas as pd
import numpy as np

url = "http://311api.cityofchicago.org/open311/v2/requests.json";
d= pd.read_json(url)     
ar = [x.get("agency_responsible") for x in d.values()] 

我收到这个错误：

Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: 'numpy.ndarray' object is not callable

然后我尝试通过添加 numpy 并处理数组来解决这个问题。

  import numpy as np
    np.[x.get("agency_responsible") for x in d.values()]

但似乎并没有成功！

我想提取 json 文件的所有值。例如我有这个对象，我想获取所有“文本”值。我怎样才能做到这一点 ？

  list= [
    {
    "text": "contact solution - COUPON",
    "listId": "1",
    "id": "4",
    "leaf": "true" 
    },
    {
    "text": "Falafel (bulk)",
    "listId": "1",
    "id": "161",
    "leaf": "true" 
    },
    {
    "text": "brita filters",
    "listId": "1",
    "id": "166",
    "leaf": "false" 
    }

输出：

listText = ["contact solution - COUPON","Falafel (bulk)","brita filters"]

更新：

我从 CSV 文件获取这些数据。

text,listId,id,leaf, jsonfile
"1","is","an","example","{ "text": "contact solution - COUPON", "listId": "1", "id": "4","leaf": "true"}"
"2","is","an","example"," { "text": "Falafel (bulk)","listId": "1", "id": "161", "leaf": "true"  }"
"3","is","an","example"," { …

我正在处理需要数小时才能执行的复杂查询.我正在使用PSycopg2

通过阅读这篇文章.我补充说:

 import os.environ
    ['PGOPTIONS'] = '-c statement_timeout=1000000'

现在,我每次都收到错误,执行此查询:

import psycopg2
>>> cnn = psycopg2.connect("dbname=test options='-c statement_timeout=1000'")
>>> cur = cnn.cursor()
>>> cur.execute("select pg_sleep(200000)")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
psycopg2.extensions.QueryCanceledError: canceling statement due to statement timeout

我的问题:如何强制应用程序花费很长时间来处理查询？