1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
|
##
## coinfetch - plugin-based cryptocurrency price converter
## Copyright (C) 2015 Delwink, LLC
##
## This program is free software: you can redistribute it and/or modify
## it under the terms of the GNU Affero General Public License as published by
## the Free Software Foundation, version 3 only.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU Affero General Public License for more details.
##
## You should have received a copy of the GNU Affero General Public License
## along with this program. If not, see <http://www.gnu.org/licenses/>.
##
from importlib.machinery import SourceFileLoader
from os import listdir
from os.path import basename, dirname, exists, expanduser, isdir, join, realpath
from requests import get
__version__ = '5.0.0'
## A cryptocurrency exchange rate ticker.
class Ticker():
## Constructor for this class.
# @param path The URL prefix for this ticker.
# @param kind Which type of exchange rate to fetch.
def __init__(self, path, kind='avg'):
self.path = path
self.kind = kind
## Defines how a currency pair is defined in the request URL.
# @param a The first currency.
# @param b The second currency.
# @return A pair string to be used in the request URL.
def get_pair(self, a, b):
return '{}_{}'.format(a, b)
## Extracts the exchange rate data from the server response.
# @param response Original response from the ticker server.
# @param The coin pair as a list/tuple.
# @return The data for the selected pair.
def get_pair_data(self, response, pair):
return response.json()[self.get_pair(pair[0], pair[1])]
## Calculates the exchange rate between two currencies.
# @param a The first currency.
# @param b The second currency.
# @param amt The number quantity of 'a' currency.
def get_rate(self, a, b, amt=1):
r = get(self.path + self.get_pair(a, b))
try:
res = self.get_pair_data(r, (a, b))
return float(res[self.kind]) * amt
except (KeyError, TypeError):
try:
r = get(self.path + self.get_pair(b, a)) # reverse order
res = self.get_pair_data(r, (b, a))
return (float(res[self.kind]) ** -1) * amt
except (KeyError, TypeError) as e:
raise ValueError(str(e)) # currency pair not found
_INDEX = {
'description': 0,
'value': 1
}
_PATH = [
dirname(realpath(__file__)),
'/usr/share/coinfetch',
'/usr/local/share/coinfetch',
join(expanduser('~'), '.coinfetch')
]
_tickers = {}
## Adds a directory to the configuration path.
# @param path The directory to be added.
def add_to_path(path):
_PATH.append(path)
## Gets the registered tickers and their descriptions.
# @return A list of tuples containing the ticker name and description.
def get_registered_tickers():
lst = []
for key in _tickers:
lst.append((key, _tickers[key][_INDEX['description']]))
return lst
## Gets a particular ticker object.
# @param key Name of the desired ticker.
# @return The Ticker object specified by 'key'.
def get_ticker(key):
return _tickers[key][_INDEX['value']]
## Registers a new ticker API.
# @param name Name of this ticker.
# @param description A brief description of this ticker.
# @param obj An instance of the ticker's implementation class.
def register_ticker(name, description, obj):
_tickers[name] = (description, obj)
## Loads a plugin or directory of plugins.
# @param path Path to the plugin file or a directory containing plugins.
def load(path):
if isdir(path):
for f in listdir(path):
if f.endswith('.py'):
load(join(path, f))
else:
SourceFileLoader('plugin', path).load_module()
## Loads all default plugins.
def load_default_plugins():
for d in _PATH:
plugindir = join(d, 'plugins')
if exists(plugindir):
load(plugindir)
## Clears the list of loaded plugins.
def unload_plugins():
global _tickers
_tickers = {}
|
