1、场景
 
表中有一个字段poschain，为json_array，但是是String类型的，无法直接通过get_json_object(poschain[0],'$.id')来获得
 
[{"gameId":"622470","traceId":"k}]
[{"gameId":"62231","traceId":"",cid":""}] 
 
2、解决办法
 
select get_json_object(poschain,'$[0].id')
from z.tta 
where date=20190507 and poschain<>'' 
limit 20;

举个例子:
 
q=[0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15]
 
我想获取其中值等于7的那个值的下标，以便于用于其他计算。
 
如果使用np.where，如：
 
 
q=np.arange(0,16,1)
 
 
g=np.where(q==7)
 
 
print q
 
 
print g
 
运行结果是:
 
 
[ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15]
 
 
(array([7]),)
 
显然(array([7]),)中的数字7我是没法提取出来做运算的，这是一个tuple。
 
 
 
--------------------
 
 
 
处理方法是:
 
 
q=np.arange(0,16,1)
 
 
g=np.argwhere(q==7)//注意这里，返回的是下标而不是索引值
 
 
print q
 
 
print g
 
 
print int(g)//转化为可运算的数字
 
运行结果为：
 
 
[ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15]
 
 
[[7]]
 
 
7
 

主要应用了argsort()函数，函数原型：
 
numpy.argsort(a, axis=-1, kind='quicksort', order=None)
'''
Returns the indices that would sort an array.

Perform an indirect sort along the given axis using the algorithm specified by the kind keyword. It returns an array of indices of the same shape as a that index data along the given axis in sorted order.
'''
Parameters:	
a : array_like
Array to sort.

axis : int or None, optional
Axis along which to sort. The default is -1 (the last axis). If None, the flattened array is used.

kind : {‘quicksort’, ‘mergesort’, ‘heapsort’, ‘stable’}, optional
Sorting algorithm.

order : str or list of str, optional
When a is an array with fields defined, this argument specifies which fields to compare first, second, etc. A single field can be specified as a string, and not all fields need be specified, but unspecified fields will still be used, in the order in which they come up in the dtype, to break ties.

Returns:	
index_array : ndarray, int
Array of indices that sort a along the specified axis. If a is one-dimensional, a[index_array] yields a sorted a. More generally, np.take_along_axis(a, index_array, axis=a) always yields the sorted a, irrespective of dimensionality.
 
 
 
示例：
 
import numpy as np
top_k=3
arr = np.array([1, 3, 2, 4, 5])
top_k_idx=arr.argsort()[::-1][0:top_k]
print(top_k_idx)
#[4 3 1]
 
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test.pphp 获取一个文件中return array() 的值hp文件
 
 
 
 
 
  

   
<?php
return array(
    'name' => 'andy',
    'sex' => 'male'
);
?>
   
 
   
 
  
 
 
 
 set.php文件 
 
 
 
 
 
  

   
<?php
$set = include("test.php");
print_r($set);exit;
?>