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authorZach White <skullydazed@users.noreply.github.com>2020-05-26 13:05:41 -0700
committerGitHub <noreply@github.com>2020-05-26 13:05:41 -0700
commit751316c34465ea77e066c3052729b207f3d62e0c (patch)
treecb99656b93c156757e2fd7c84fe716f9c300ca89 /lib/python/qmk/math.py
parent5d3bf8a050f3c0beb1f91147dc1ab54de36cbb05 (diff)
downloadqmk_firmware-751316c34465ea77e066c3052729b207f3d62e0c.tar.gz
qmk_firmware-751316c34465ea77e066c3052729b207f3d62e0c.zip
[CLI] Add a subcommand for getting information about a keyboard (#8666)
You can now use `qmk info` to get information about keyboards and keymaps. Co-authored-by: Erovia <Erovia@users.noreply.github.com>
Diffstat (limited to 'lib/python/qmk/math.py')
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diff --git a/lib/python/qmk/math.py b/lib/python/qmk/math.py
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1"""Parse arbitrary math equations in a safe way.
2
3Gratefully copied from https://stackoverflow.com/a/9558001
4"""
5import ast
6import operator as op
7
8# supported operators
9operators = {ast.Add: op.add, ast.Sub: op.sub, ast.Mult: op.mul, ast.Div: op.truediv, ast.Pow: op.pow, ast.BitXor: op.xor, ast.USub: op.neg}
10
11
12def compute(expr):
13 """Parse a mathematical expression and return the answer.
14
15 >>> compute('2^6')
16 4
17 >>> compute('2**6')
18 64
19 >>> compute('1 + 2*3**(4^5) / (6 + -7)')
20 -5.0
21 """
22 return _eval(ast.parse(expr, mode='eval').body)
23
24
25def _eval(node):
26 if isinstance(node, ast.Num): # <number>
27 return node.n
28 elif isinstance(node, ast.BinOp): # <left> <operator> <right>
29 return operators[type(node.op)](_eval(node.left), _eval(node.right))
30 elif isinstance(node, ast.UnaryOp): # <operator> <operand> e.g., -1
31 return operators[type(node.op)](_eval(node.operand))
32 else:
33 raise TypeError(node)