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Print number of keys in Redis
...of keys and 'expires' indicates no of keys with expiry set. Essentially it means that they have a ttl set and they are set to expire, not that they have expired.
– s1d
How to update SQLAlchemy row entry?
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@ChaimG I guess you meant user.no_of_logins = User.no_of_logins + 1, or in other words use the instrumented attribute of the model to produce an SQL expression. As it is your comment displays 2 ways to produce the same race condition.
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Why do we need tuples in Python (or any immutable data type)?
...y significant. Try python -mtimeit -s "x=23" "[x,x]" and you'll see a more meaningful speedup of 2-3 times for building the tuple vs building the list.
– Alex Martelli
Feb 1 '10 at 21:23
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When do you use map vs flatMap in RxJava?
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flatMap - supplied function accepts an item then returns an "Observable", meaning each item of the new "Observable" will be emitted separately further down.
May be code will clear things up for you:
Observable.just("item1").map( str -> {
System.out.println("inside the map " + str);
re...
How to launch an Activity from another Application in Android
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How to run it in background? Means second called applications doesn't show on screen, but run its onCreated() method.
– Dr.jacky
Sep 8 '16 at 7:26
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Select rows which are not present in other table
...@MatthiasFripp: Except that this can never occur with WHERE i.ip IS NULL, meaning no match at all.
– Erwin Brandstetter
Jun 4 at 0:40
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Difference between two dates in Python
...t=data['1st Gift']
last=data['Last Gift']
maxi=data['Largest Gift']
l_1=np.mean(first)-3*np.std(first)
u_1=np.mean(first)+3*np.std(first)
m=np.abs(data['1st Gift']-np.mean(data['1st Gift']))>3*np.std(data['1st Gift'])
pd.value_counts(m)
l=first[m]
data.loc[:,'1st Gift'][m==True]=np.mean(data['1...
Flat file databases [closed]
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In my opinion, using a "Flat File Database" in the sense you're meaning (and the answer you've accepted) isn't necessarily the best way to go about things. First of all, using serialize() and unserialize() can cause MAJOR headaches if someone gets in and edits the file (they can, in fact,...
What does the star operator mean, in a function call?
What does the * operator mean in Python, such as in code like zip(*x) or f(**k) ?
5 Answers
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Django self-referential foreign key
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I think you mean 'self'. As in the string. self is undefined in this context
– Jared Forsyth
Mar 8 '13 at 2:28
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