StackStorm /
st2
| Conditions | 11 |
| Total Lines | 65 |
| 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 st2common.models.utils.ActionAliasFormatParser.get_extracted_param_value() 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 | # Licensed to the StackStorm, Inc ('StackStorm') under one or more |
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| 30 | def get_extracted_param_value(self): |
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| 31 | |||
| 32 | result = {} |
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| 33 | |||
| 34 | # As there's a lot of questions about using regular expressions, |
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| 35 | # I'll try to be thorough when documenting this code. |
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| 36 | |||
| 37 | # We're parsing the arbitrary key-value pairs at the end of the stream |
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| 38 | # to support passing of parameters not specified in the format string, |
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| 39 | # and cutting them from the stream as they're no longer needed. |
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| 40 | # Possible values are quoted strings, a word, or anything inside "{}". |
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| 41 | pairs_match = r'(?:^|\s+)(\S+)=("(.*?)"|\'(.*?)\'|({.*?})|(\S+))' |
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| 42 | extra = re.match(r'.*?((' + pairs_match + r'\s*)*)$', |
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| 43 | self._param_stream, re.DOTALL) |
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| 44 | if extra: |
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| 45 | kv_pairs = re.findall(pairs_match, |
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| 46 | extra.group(1), re.DOTALL) |
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| 47 | self._param_stream = self._param_stream.replace(extra.group(1), '') |
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| 48 | self._param_stream = " %s " % self._param_stream |
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| 49 | |||
| 50 | # Now we'll match parameters with default values in form of |
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| 51 | # {{ value = parameter }} (and all possible permutations of spaces), |
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| 52 | # compiling them into a list. |
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| 53 | # "test {{ url = http://google.com }} {{ extra = Test }}" will become |
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| 54 | # [ ["url", "http://google.com"], ["extra", "Test"] ] |
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| 55 | params = re.findall(r'{{\s*(.+?)\s*(?:=\s*[\'"]?({.+?}|.+?)[\'"]?)?\s*}}', |
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| 56 | self._format, re.DOTALL) |
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| 57 | |||
| 58 | # Now we're transforming our format string into a regular expression, |
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| 59 | # substituting {{ ... }} with regex named groups, so that param_stream |
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| 60 | # matched against this expression yields a dict of params with values. |
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| 61 | param_match = r'["\']?(?P<\2>(?:(?<=\').+?(?=\')|(?<=").+?(?=")|{.+?}|.+?))["\']?' |
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| 62 | reg = re.sub(r'(\s*){{\s*([^=}]+?)\s*}}(?![\'"]?\s+}})', |
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| 63 | r'\1' + param_match, |
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| 64 | self._format) |
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| 65 | reg = re.sub(r'(\s*){{\s*(\S+)\s*=\s*(?:{.+?}|.+?)\s*}}', |
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| 66 | r'(?:\1' + param_match + r')?', |
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| 67 | reg) |
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| 68 | reg = re.sub(r'(\s*){{\s*(.+?)\s*}}', |
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| 69 | r'\1' + param_match, |
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| 70 | reg) |
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| 71 | reg = '^\s*' + reg + r'\s*$' |
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| 72 | |||
| 73 | # Now we're matching param_stream against our format string regex, |
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| 74 | # getting a dict of values. We'll also get default values from |
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| 75 | # "params" list if something is not present. |
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| 76 | # Priority, from lowest to highest: |
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| 77 | # 1. Default parameters |
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| 78 | # 2. Matched parameters |
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| 79 | # 3. Extra parameters |
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| 80 | matched_stream = re.match(reg, self._param_stream, re.DOTALL) |
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| 81 | if matched_stream: |
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| 82 | values = matched_stream.groupdict() |
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| 83 | for param in params: |
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| 84 | matched_value = values[param[0]] if matched_stream else param[1] or None |
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| 85 | if matched_value: |
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| 86 | result[param[0]] = matched_value |
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| 87 | if extra: |
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| 88 | for pair in kv_pairs: |
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| 89 | result[pair[0]] = ''.join(pair[2:]) |
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| 90 | |||
| 91 | if self._format and not (self._param_stream.strip() or any(result.values())): |
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| 92 | raise content.ParseException('No value supplied and no default value found.') |
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| 93 | |||
| 94 | return result |
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| 95 |
Escape sequences in Python are generally interpreted according to rules similar to standard C. Only if strings are prefixed with
rorRare they interpreted as regular expressions.The escape sequence that was used indicates that you might have intended to write a regular expression.
Learn more about the available escape sequences. in the Python documentation.