Passed
Push — master ( 2f219c...d7053c )
by Rafael S.
01:30
created

Occurrence.update_holder()   B

Complexity

Conditions 5

Size

Total Lines 63

Duplication

Lines 0
Ratio 0 %

Importance

Changes 0
Metric Value
cc 5
dl 0
loc 63
rs 8.3013
c 0
b 0
f 0

How to fix   Long Method   

Long Method

Small methods make your code easier to understand, in particular if combined with a good name. Besides, if your method is small, finding a good name is usually much easier.

For example, if you find yourself adding comments to a method's body, this is usually a good sign to extract the commented part to a new method, and use the comment as a starting point when coming up with a good name for this new method.

Commonly applied refactorings include:

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"""Occurrence
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A class to represent occurrences with subjects.
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https://github.com/rochars/trade
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License: MIT
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Copyright (c) 2015-2018 Rafael da Silva Rocha
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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THE SOFTWARE.
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"""
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from __future__ import absolute_import
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from __future__ import division
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import math
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class Occurrence(object):
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    """A class to represent occurrences with subjects.
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    Attributes:
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        subject: A Subject instance.
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        date: A string to represent the moment of the occurrence.
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        details: A dictionary with the occurrence details.
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    """
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    def __init__(self, subject, date, details):
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        self.subject = subject
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        self.date = date
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        self.details = details
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    def update_holder(self, holder):
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        """Udpate the Holder state according to the occurrence.
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        This implementation is a example of how a Occurrence object
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        can update the Holder state; this method should be overriden
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        by classes that inherit from the Occurrence class.
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        This sample implementation simply update the quantity and the average
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        price of the Subject in the Holder's possession every time objects
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        from this class are passed to Holder.trade().
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        This sample implementation considers the following signature for
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        the Holder.state dictionary:
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            {
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                "SUBJECT SYMBOL": {
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                    "quantity": 0,
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                    "value": 0
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                },
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                ...
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            }
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        """
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        subject_symbol = self.subject.symbol
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        # If the Holder already have a state regarding this Subject,
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        # update that state
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        if subject_symbol in holder.state:
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            # If the Holder have zero units of this subject, the average
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            # value paid/received for the subject is the value of the trade itself
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            if not holder.state[subject_symbol]['quantity']:
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                holder.state[subject_symbol]['value'] = self.details['value']
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            # If the Holder owns units of this subject then the average value
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            # paid/received for the subject may need to be updated with
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            # this occurrence details
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            elif same_sign(
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                    holder.state[subject_symbol]['quantity'],
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                    self.details['quantity']):
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                holder.state[subject_symbol]['value'] = average_price(
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                    holder.state[subject_symbol]['quantity'],
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                    holder.state[subject_symbol]['value'],
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                    self.details['quantity'],
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                    self.details['value']
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                )
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            # Update the quantity of the subject in the Holder's posession
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            holder.state[subject_symbol]['quantity'] += self.details['quantity']
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        # If the Holder don't have a state with this occurrence's Subject,
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        # then register this occurrence as the first state of the Subject 
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        # in the Holder's possession
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        else:
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            holder.state[subject_symbol] = {
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                'quantity': self.details['quantity'],
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                'value': self.details['value']
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            }
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        # If the Holder knows about this Subject but don't have any unit
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        # of it, the paid value of the subject in the Holder state should
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        # be zero.
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        if not holder.state[subject_symbol]['quantity']:
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            holder.state[subject_symbol]['value'] = 0
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def average_price(quantity_1, price_1, quantity_2, price_2):
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    """Calculates the average price between two asset states."""
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    return (quantity_1 * price_1 + quantity_2 * price_2) / \
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            (quantity_1 + quantity_2)
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def same_sign(number_1, number_2):
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    """Checks if two numbers have the same sign."""
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    return (number_1 >= 0) ^ (number_2 < 0)
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