如何使用python划分列表的两个元素

Question

I have python code as follow. jv_list is populated from resultset retrieve from DB query.

jv_list = list(result.get_points())
print(jv_list)

I am printing jv_list and it is giving me below mention output.

[{u'in': u'19834', u'length-bytes': u'79923888', u'run-time': u'1h50m43.489993955s', u'time': u'2017-09-08T21:20:39.846582783Z'}]

How can i get division result which is actually second value divided by first value. for. ie 79923888/ 19834

Answer 1

Try this sequence of commands

>>> X = [{u'in': u'19834', u'length-bytes': u'79923888', u'run-time': u'1h50m43.489993955s', u'time': u'2017-09-08T21:20:39.846582783Z'}]
>>> for x in X:
...     x['answer'] = float(x['length-bytes'])/float(x['in'])
...
>>> X
[{'in': '19834', 'length-bytes': '79923888', 'run-time': '1h50m43.489993955s', 'time': '2017-09-08T21:20:39.846582783Z', 'answer': 4029.64041544822}]

Answer 2

If this is what you mean

x = [{u'in': u'19834', u'length-bytes': u'79923888', u'run-time': u'1h50m43.489993955s', u'time': u'2017-09-08T21:20:39.846582783Z'}]
for i in x:
    print(float(i['length-bytes'])/float(i['in']))

results as

4029.64041544822

Answer 3

You can't reliably do that, dictionaries are unordered.
With this data structure, you will need to address the elements via their keys.

that is jv_list[0]['length_bytes'] / jv_list[0]['in'] for each pair of elements you want to divide by each other.

Answer 4

If you want the result of length-bytes / in , you can use those keys and retrieve their values:

jv_list = [{u'in': u'19834', u'length-bytes': u'79923888', u'run-time': u'1h50m43.489993955s', u'time': u'2017-09-08T21:20:39.846582783Z'}]

result = float(jv_list[0]['length-bytes']) / float(jv_list[0]['in'])
print(result) # => 4029.64041544822

Answer 5

根据您的数据结构，看来这将是答案。

float(jv_list[0]['length-bytes']) / float(jv_list[0]['in'])