Conditions | 16 |
Total Lines | 58 |
Lines | 0 |
Ratio | 0 % |
Changes | 3 | ||
Bugs | 0 | Features | 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 PortRange.parse() 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 | # -*- coding: utf-8 -*- |
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64 | def parse(self, port_range): |
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65 | """ Parse and normalize a string or iterable into a port range. """ |
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66 | # Any string containing a CIDR separator is parsed as a CIDR-like |
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67 | # notation, others as a range or single port. |
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68 | cidr_notation = False |
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69 | if isinstance(port_range, basestring): |
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70 | cidr_notation = self.CIDR_SEP in port_range |
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71 | separator = self.CIDR_SEP if cidr_notation else self.RANGE_SEP |
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72 | port_range = port_range.split(separator, 1) |
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73 | |||
74 | # We expect here a list of elements castable to integers. |
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75 | if not isinstance(port_range, Iterable): |
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76 | port_range = [port_range] |
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77 | try: |
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78 | port_range = list(iter_map(int, port_range)) |
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79 | except TypeError: |
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80 | raise ValueError("Can't parse range as a list of integers.") |
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81 | |||
82 | # At this point we should have a list of one or two integers. |
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83 | if not 0 < len(port_range) < 3: |
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84 | raise ValueError("Expecting a list of one or two elements.") |
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85 | |||
86 | # Transform CIDR notation into a port range and validates it. |
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87 | if cidr_notation: |
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88 | base, prefix = port_range |
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89 | port_range = self._cidr_to_range(base, prefix) |
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90 | |||
91 | # Let the parser fix a reverse-ordered range in non-strict mode. |
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92 | if not self.strict: |
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93 | port_range.sort() |
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94 | |||
95 | # Get port range bounds. |
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96 | port_from = port_range[0] |
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97 | # Single port gets their upper bound set to None. |
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98 | port_to = port_range[1] if len(port_range) == 2 else None |
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99 | |||
100 | # Validate constraints in strict mode. |
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101 | if self.strict: |
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102 | # Disallow out-of-bounds values. |
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103 | if not (self.port_min <= port_from <= self.port_max) or ( |
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104 | port_to is not None and not ( |
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105 | self.port_min <= port_to <= self.port_max)): |
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106 | raise ValueError("Out of bounds.") |
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107 | # Disallow reversed range. |
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108 | if port_to is not None and port_from > port_to: |
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109 | raise ValueError("Invalid reversed port range.") |
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110 | |||
111 | # Clamp down lower bound, then cap it. |
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112 | port_from = min([max([port_from, self.port_min]), self.port_max]) |
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113 | |||
114 | # Single port gets its upper bound aligned to its lower one. |
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115 | if port_to is None: |
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116 | port_to = port_from |
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117 | |||
118 | # Cap upper bound. |
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119 | port_to = min([port_to, self.port_max]) |
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120 | |||
121 | return port_from, port_to |
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122 | |||
234 |