Util¶
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class
praw.models.util.
BoundedSet
(max_items)¶ A set with a maximum size that evicts the oldest items when necessary.
This class does not implement the complete set interface.
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__contains__
(item)¶ Test if the BoundedSet contains item.
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__init__
(max_items)¶ Construct an instance of the BoundedSet.
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add
(item)¶ Add an item to the set discarding the oldest item if necessary.
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class
praw.models.util.
ExponentialCounter
(max_counter)¶ A class to provide an exponential counter with jitter.
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__init__
(max_counter)¶ Initialize an instance of ExponentialCounter.
Parameters: max_counter – The maximum base value. Note that the computed value may be 3.125% higher due to jitter.
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counter
()¶ Increment the counter and return the current value with jitter.
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reset
()¶ Reset the counter to 1.
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util.
permissions_string
(permissions, known_permissions)¶ Return a comma separated string of permission changes.
Parameters: - permissions – A list of strings, or
None
. These strings can exclusively contain+
or-
prefixes, or contain no prefixes at all. When prefixed, the resulting string will simply be the joining of these inputs. When not prefixed, all permissions are considered to be additions, and all permissions in theknown_permissions
set that aren’t provided are considered to be removals. When None, the result is+all
. - known_permissions – A set of strings representing the available permissions.
- permissions – A list of strings, or
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util.
stream_generator
(function, pause_after=None)¶ Yield new items from ListingGenerators and
None
when paused.Parameters: - function – A callable that returns a ListingGenerator, e.g.
subreddit.comments
orsubreddit.new
. - pause_after – An integer representing the number of requests that
result in no new items before this function yields
None
, effectively introducing a pause into the stream. A negative value yieldsNone
after items from a single response have been yielded, regardless of number of new items obtained in that response. A value of0
yieldsNone
after every response resulting in no new items, and a value ofNone
never introduces a pause (default: None).
Note
This function internally uses an exponential delay with jitter between subsequent responses that contain no new results, up to a maximum delay of just over a 16 seconds. In practice that means that the time before pause for
pause_after=N+1
is approximately twice the time before pause forpause_after=N
.For example to pause a comment stream after six responses with no new comments, try:
subreddit = reddit.subreddit('redditdev') for comment in subreddit.stream.comments(pause_after=6): if comment is None: break print(comment)
To resume fetching comments after a pause, try:
subreddit = reddit.subreddit('help') comment_stream = subreddit.stream.comments(pause_after=5) for comment in comment_stream: if comment is None: break print(comment) # Do any other processing, then try to fetch more data for comment in comment_stream: if comment is None: break print(comment)
To bypass the internal exponential backoff, try the following. This approach is useful if you are monitoring a subreddit with infrequent activity, and you want the to consistently learn about new items from the stream as soon as possible, rather than up to a delay of just over sixteen seconds.
subreddit = reddit.subreddit('help') for comment in subreddit.stream.comments(pause_after=0): if comment is None: continue print(comment)
- function – A callable that returns a ListingGenerator, e.g.