| Conditions | 18 |
| Total Lines | 83 |
| Lines | 0 |
| Ratio | 0 % |
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:
If many parameters/temporary variables are present:
Complex classes like parse_label_vector() often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
| 1 | #!/usr/bin/env python |
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| 62 | def parse_label_vector(label_vector_description, columns=None, **kwargs): |
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| 63 | """ |
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| 64 | Return a structured form of a label vector from unstructured, |
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| 65 | human-readable input. |
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| 66 | |||
| 67 | :param label_vector_description: |
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| 68 | A human-readable or structured form of a label vector. |
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| 69 | |||
| 70 | :type label_vector_description: |
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| 71 | str or list |
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| 72 | |||
| 73 | :param columns: [optional] |
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| 74 | If `columns` are provided, instead of text columns being provided as the |
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| 75 | output parameter, the corresponding index location in `column` will be |
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| 76 | given. |
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| 77 | |||
| 78 | :returns: |
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| 79 | A structured form of the label vector as a multi-level list. |
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| 80 | |||
| 81 | |||
| 82 | :Example: |
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| 83 | |||
| 84 | >>> parse_label_vector("Teff^4 + logg*Teff^3 + feh + feh^0*Teff") |
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| 85 | [ |
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| 86 | [ |
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| 87 | ("Teff", 4), |
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| 88 | ], |
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| 89 | [ |
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| 90 | ("logg", 1), |
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| 91 | ("Teff", 3) |
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| 92 | ], |
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| 93 | [ |
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| 94 | ("feh", 1), |
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| 95 | ], |
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| 96 | [ |
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| 97 | ("feh", 0), |
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| 98 | ("Teff", 1) |
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| 99 | ] |
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| 100 | ] |
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| 101 | """ |
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| 102 | |||
| 103 | if is_structured_label_vector(label_vector_description): |
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| 104 | return label_vector_description |
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| 105 | |||
| 106 | # Allow for custom characters, but don't advertise it. |
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| 107 | # (Astronomers have bad enough habits already.) |
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| 108 | kwds = dict(zip(("sep", "mul", "pow"), "+*^")) |
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| 109 | kwds.update(kwargs) |
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| 110 | sep, mul, pow = (kwds[k] for k in ("sep", "mul", "pow")) |
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| 111 | |||
| 112 | if isinstance(label_vector_description, string_types): |
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| 113 | label_vector_description = label_vector_description.split(sep) |
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| 114 | label_vector_description = map(str.strip, label_vector_description) |
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| 115 | |||
| 116 | # Functions to parse the parameter (or index) and order for each term. |
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| 117 | get_power = lambda t: float(t.split(pow)[1].strip()) if pow in t else 1 |
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| 118 | if columns is None: |
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| 119 | get_label = lambda d: d.split(pow)[0].strip() |
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| 120 | else: |
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| 121 | get_label = lambda d: list(columns).index(d.split(pow)[0].strip()) |
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| 122 | |||
| 123 | label_vector = [] |
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| 124 | for descriptor in (item.split(mul) for item in label_vector_description): |
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| 125 | |||
| 126 | labels = map(get_label, descriptor) |
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| 127 | orders = map(get_power, descriptor) |
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| 128 | |||
| 129 | term = OrderedDict() |
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| 130 | for label, order in zip(labels, orders): |
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| 131 | term[label] = term.get(label, 0) + order # Sum repeat term powers. |
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| 132 | |||
| 133 | # Prevent uses of x^0 etc clogging up the label vector. |
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| 134 | valid_terms = [(l, o) for l, o in term.items() if o != 0] |
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| 135 | if not np.all(np.isfinite([o for l, o in valid_terms])): |
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| 136 | raise ValueError("non-finite power provided") |
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| 137 | |||
| 138 | if len(valid_terms) > 0: |
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| 139 | label_vector.append(valid_terms) |
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| 140 | |||
| 141 | if sum(map(len, label_vector)) == 0: |
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| 142 | raise ValueError("no valid terms provided") |
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| 143 | |||
| 144 | return label_vector |
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| 145 | |||
| 258 |