50 lines
1.6 KiB
Python
50 lines
1.6 KiB
Python
# piker: trading gear for hackers
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# Copyright (C) 2018-present Tyler Goodlet (in stewardship of piker0)
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU Affero General Public License as published by
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# the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU Affero General Public License for more details.
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# You should have received a copy of the GNU Affero General Public License
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# along with this program. If not, see <https://www.gnu.org/licenses/>.
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"""
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Handy financial calculations.
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"""
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import math
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import itertools
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def humanize(number, digits=1):
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"""Convert large numbers to something with at most 3 digits and
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a letter suffix (eg. k: thousand, M: million, B: billion).
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"""
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try:
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float(number)
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except ValueError:
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return 0
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if not number or number <= 0:
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return number
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mag2suffix = {3: 'k', 6: 'M', 9: 'B'}
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mag = math.floor(math.log(number, 10))
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if mag < 3:
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return number
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maxmag = max(itertools.takewhile(lambda key: mag >= key, mag2suffix))
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return "{:.{digits}f}{}".format(
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number/10**maxmag, mag2suffix[maxmag], digits=digits)
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def percent_change(init, new):
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"""Calcuate the percentage change of some ``new`` value
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from some initial value, ``init``.
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"""
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if not (init and new):
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return 0
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return (new - init) / init * 100.
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