| 1 | """ |
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| 2 | Utilities for turning objects into human-readable strings. |
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| 3 | |
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| 4 | This module has been ported to Python 3. |
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| 5 | """ |
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| 6 | |
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| 7 | import os |
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| 8 | from reprlib import Repr |
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| 9 | |
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| 10 | class BetterRepr(Repr, object): |
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| 11 | def __init__(self): |
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| 12 | Repr.__init__(self) |
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| 13 | |
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| 14 | # Note: These levels can get adjusted dynamically! My goal is to get more info when printing important debug stuff like exceptions and stack traces and less info when logging normal events. --Zooko 2000-10-14 |
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| 15 | self.maxlevel = 6 |
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| 16 | self.maxdict = 6 |
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| 17 | self.maxlist = 6 |
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| 18 | self.maxtuple = 6 |
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| 19 | self.maxstring = 300 |
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| 20 | self.maxother = 300 |
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| 21 | |
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| 22 | def repr_function(self, obj, level): |
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| 23 | if hasattr(obj, '__code__'): |
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| 24 | return '<' + obj.__name__ + '() at ' + os.path.basename(obj.__code__.co_filename) + ':' + str(obj.__code__.co_firstlineno) + '>' |
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| 25 | else: |
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| 26 | return '<' + obj.__name__ + '() at (builtin)' |
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| 27 | |
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| 28 | def repr_instance_method(self, obj, level): |
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| 29 | if hasattr(obj, '__code__'): |
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| 30 | return '<' + obj.__self__.__class__.__name__ + '.' + obj.__func__.__name__ + '() at ' + os.path.basename(obj.__func__.__code__.co_filename) + ':' + str(obj.__func__.__code__.co_firstlineno) + '>' |
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| 31 | else: |
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| 32 | return '<' + obj.__self__.__class__.__name__ + '.' + obj.__func__.__name__ + '() at (builtin)' |
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| 33 | |
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| 34 | def repr_long(self, obj, level): |
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| 35 | s = repr(obj) # XXX Hope this isn't too slow... |
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| 36 | if len(s) > self.maxlong: |
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| 37 | i = max(0, (self.maxlong-3) // 2) |
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| 38 | j = max(0, self.maxlong-3-i) |
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| 39 | s = s[:i] + '...' + s[len(s)-j:] |
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| 40 | if s[-1] == 'L': |
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| 41 | return s[:-1] |
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| 42 | return s |
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| 43 | |
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| 44 | def repr_instance(self, obj, level): |
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| 45 | """ |
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| 46 | If it is an instance of Exception, format it nicely (trying to emulate |
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| 47 | the format that you see when an exception is actually raised, plus |
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| 48 | bracketing '<''s). If it is an instance of dict call self.repr_dict() |
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| 49 | on it. If it is an instance of list call self.repr_list() on it. Else |
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| 50 | call Repr.repr_instance(). |
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| 51 | """ |
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| 52 | if isinstance(obj, Exception): |
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| 53 | # Don't cut down exception strings so much. |
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| 54 | tms = self.maxstring |
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| 55 | self.maxstring = max(512, tms * 4) |
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| 56 | tml = self.maxlist |
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| 57 | self.maxlist = max(12, tml * 4) |
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| 58 | try: |
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| 59 | if hasattr(obj, 'args'): |
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| 60 | if len(obj.args) == 1: |
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| 61 | return '<' + obj.__class__.__name__ + ': ' + self.repr1(obj.args[0], level-1) + '>' |
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| 62 | else: |
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| 63 | return '<' + obj.__class__.__name__ + ': ' + self.repr1(obj.args, level-1) + '>' |
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| 64 | else: |
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| 65 | return '<' + obj.__class__.__name__ + '>' |
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| 66 | finally: |
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| 67 | self.maxstring = tms |
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| 68 | self.maxlist = tml |
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| 69 | |
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| 70 | if isinstance(obj, dict): |
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| 71 | return self.repr_dict(obj, level) |
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| 72 | |
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| 73 | if isinstance(obj, list): |
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| 74 | return self.repr_list(obj, level) |
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| 75 | |
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| 76 | return Repr.repr_instance(self, obj, level) |
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| 77 | |
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| 78 | def repr_list(self, obj, level): |
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| 79 | """ |
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| 80 | copied from standard repr.py and fixed to work on multithreadedly mutating lists. |
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| 81 | """ |
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| 82 | if level <= 0: return '[...]' |
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| 83 | n = len(obj) |
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| 84 | myl = obj[:min(n, self.maxlist)] |
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| 85 | s = '' |
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| 86 | for item in myl: |
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| 87 | entry = self.repr1(item, level-1) |
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| 88 | if s: s = s + ', ' |
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| 89 | s = s + entry |
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| 90 | if n > self.maxlist: s = s + ', ...' |
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| 91 | return '[' + s + ']' |
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| 92 | |
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| 93 | def repr_dict(self, obj, level): |
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| 94 | """ |
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| 95 | copied from standard repr.py and fixed to work on multithreadedly mutating dicts. |
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| 96 | """ |
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| 97 | if level <= 0: return '{...}' |
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| 98 | s = '' |
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| 99 | n = len(obj) |
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| 100 | items = list(obj.items())[:min(n, self.maxdict)] |
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| 101 | items.sort() |
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| 102 | for key, val in items: |
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| 103 | entry = self.repr1(key, level-1) + ':' + self.repr1(val, level-1) |
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| 104 | if s: s = s + ', ' |
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| 105 | s = s + entry |
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| 106 | if n > self.maxdict: s = s + ', ...' |
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| 107 | return '{' + s + '}' |
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| 108 | |
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| 109 | # This object can be changed by other code updating this module's "brepr" |
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| 110 | # variables. This is so that (a) code can use humanreadable with |
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| 111 | # "from humanreadable import hr; hr(mything)", and (b) code can override |
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| 112 | # humanreadable to provide application-specific human readable output |
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| 113 | # (e.g. libbase32's base32id.AbbrevRepr). |
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| 114 | brepr = BetterRepr() |
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| 115 | |
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| 116 | def hr(x): |
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| 117 | return brepr.repr(x) |
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