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How to convert nanoseconds to seconds using the TimeUnit enum?
... This answer is now wrong - convert() and the toFoo() methods all return longs now docs.oracle.com/javase/6/docs/api/java/util/concurrent/…
– Riking
Jul 30 '13 at 1:58
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What is the difference between the dot (.) operator and -> in C++? [duplicate]
...force this with parenthesis:
(*pointervariable).foo
But typing the ()'s all the time is hard, so they developed -> as a shortcut to say the same thing. If you are accessing a property of an object or object reference, use . If you are accessing a property of an object through a pointer, use -...
Make UINavigationBar transparent
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Undoing the effect for me only partially works. Because after I do this, my tableviews all have headers that are too large. App-wide, which is weird. (I only want this effect for one controller that I push on the stack.)
– Henning
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How do I get an empty array of any size in python?
I basically want a python equivalent of this in C:
8 Answers
8
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Pandas DataFrame Groupby two columns and get counts
...er,
You need to provide one more column which counts the grouping, let's call that column as, "COUNTER" in dataframe.
Like this:
df['COUNTER'] =1 #initially, set that counter to 1.
group_data = df.groupby(['Alphabet','Words'])['COUNTER'].sum() #sum function
print(group_data)
OUTPUT:
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How to print like printf in Python3?
... inline interpolation. What's even nicer is it extended the syntax to also allow format specifiers with interpolation. Something I've been working on while I googled this (and came across this old question!):
print(f'{account:40s} ({ratio:3.2f}) -> AUD {splitAmount}')
PEP 498 has the details. ...
Determine the number of NA values in a column
...nt the number of NA values in a data frame column. Say my data frame is called df , and the name of the column I am considering is col . The way I have come up with is following:
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Rails 3 migrations: Adding reference column?
...d:
rails g migration add_user_id_to_tester user_id:integer
And then manually add belongs_to :user in the Tester model
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UnmodifiableMap (Java Collections) vs ImmutableMap (Google) [duplicate]
...// Will return "F".
In contrast to that, the ImmutableMap of Guava is really immutable: It is a true copy of a given map, and nobody may modify this ImmutableMap in any way.
Update:
As pointed out in a comment, an immutable map can also be created with the standard API using
Map<String, S...
Getting the first index of an object
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For a one liner to work in all browsers including IE8 and below use for (var key in obj) if (obj.hasOwnProperty(key)) break; You'll then want to use the key variable
– Ally
Sep 6 '13 at 16:23
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