1 | """Occurrence |
||
2 | |||
3 | A class to represent occurrences with subjects. |
||
4 | |||
5 | https://github.com/rochars/trade |
||
6 | License: MIT |
||
7 | |||
8 | Copyright (c) 2015-2018 Rafael da Silva Rocha |
||
9 | |||
10 | Permission is hereby granted, free of charge, to any person obtaining a copy |
||
11 | of this software and associated documentation files (the "Software"), to deal |
||
12 | in the Software without restriction, including without limitation the rights |
||
13 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
||
14 | copies of the Software, and to permit persons to whom the Software is |
||
15 | furnished to do so, subject to the following conditions: |
||
16 | |||
17 | The above copyright notice and this permission notice shall be included in |
||
18 | all copies or substantial portions of the Software. |
||
19 | |||
20 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
||
21 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
||
22 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
||
23 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
||
24 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
||
25 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
||
26 | THE SOFTWARE. |
||
27 | """ |
||
28 | |||
29 | from __future__ import absolute_import |
||
30 | from __future__ import division |
||
31 | |||
32 | |||
33 | class Occurrence(object): |
||
0 ignored issues
–
show
Unused Code
introduced
by
Loading history...
|
|||
34 | """A class to represent occurrences with subjects. |
||
35 | |||
36 | Attributes: |
||
37 | subject: A Subject instance. |
||
38 | date: A string to represent the moment of the occurrence. |
||
39 | details: A dict with the occurrence details. |
||
40 | """ |
||
41 | |||
42 | def __init__(self, subject, date, details): |
||
43 | self.subject = subject |
||
44 | self.date = date |
||
45 | self.details = details |
||
46 | |||
47 | def update_holder(self, holder): |
||
48 | """Udpate the Holder state according to the occurrence. |
||
49 | |||
50 | This implementation is a example of how a Occurrence object |
||
51 | can update the Holder state; this method should be overriden |
||
52 | by classes that inherit from the Occurrence class. |
||
53 | |||
54 | This sample implementation simply update the quantity and the average |
||
55 | price of the Subject in the Holder's possession every time objects |
||
56 | from this class are passed to Holder.trade(). |
||
57 | |||
58 | This sample implementation considers the following signature for |
||
59 | the Holder.state dict: |
||
60 | { |
||
61 | "SUBJECT SYMBOL": { |
||
62 | "quantity": 0, |
||
63 | "value": 0 |
||
64 | }, |
||
65 | ... |
||
66 | } |
||
67 | |||
68 | And the following signature for the Occurrance.details dict: |
||
69 | { |
||
70 | "quantity": 0, |
||
71 | "value": 0 |
||
72 | } |
||
73 | """ |
||
74 | |||
75 | subject_symbol = self.subject.symbol |
||
76 | |||
77 | # If the Holder already have a state regarding this Subject, |
||
78 | # update that state |
||
79 | if subject_symbol in holder.state: |
||
80 | |||
81 | # If the Holder have zero units of this subject, the average |
||
82 | # value paid/received for the subject is the value of the trade itself |
||
83 | if not holder.state[subject_symbol]['quantity']: |
||
84 | holder.state[subject_symbol]['value'] = self.details['value'] |
||
85 | |||
86 | # If the Holder owns units of this subject then the average value |
||
87 | # paid/received for the subject may need to be updated with |
||
88 | # this occurrence details |
||
89 | elif same_sign( |
||
90 | holder.state[subject_symbol]['quantity'], |
||
91 | self.details['quantity']): |
||
92 | holder.state[subject_symbol]['value'] = average_price( |
||
93 | holder.state[subject_symbol]['quantity'], |
||
94 | holder.state[subject_symbol]['value'], |
||
95 | self.details['quantity'], |
||
96 | self.details['value'] |
||
97 | ) |
||
98 | |||
99 | # Update the quantity of the subject in the Holder's posession |
||
100 | holder.state[subject_symbol]['quantity'] += self.details['quantity'] |
||
101 | |||
102 | # If the Holder don't have a state with this occurrence's Subject, |
||
103 | # then register this occurrence as the first state of the Subject |
||
104 | # in the Holder's possession |
||
105 | else: |
||
106 | holder.state[subject_symbol] = { |
||
107 | 'quantity': self.details['quantity'], |
||
108 | 'value': self.details['value'] |
||
109 | } |
||
110 | |||
111 | # If the Holder knows about this Subject but don't have any unit |
||
112 | # of it, the paid value of the subject in the Holder state should |
||
113 | # be zero. |
||
114 | if not holder.state[subject_symbol]['quantity']: |
||
115 | holder.state[subject_symbol]['value'] = 0 |
||
116 | |||
117 | def average_price(quantity_1, price_1, quantity_2, price_2): |
||
118 | """Calculates the average price between two asset states.""" |
||
119 | return (quantity_1 * price_1 + quantity_2 * price_2) / \ |
||
120 | (quantity_1 + quantity_2) |
||
121 | |||
122 | def same_sign(number_1, number_2): |
||
123 | """Checks if two numbers have the same sign.""" |
||
124 | return (number_1 >= 0) ^ (number_2 < 0) |
||
125 |