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How do I get the row count of a pandas DataFrame?
I'm trying to get the number of rows of dataframe df with Pandas, and here is my code.
14 Answers
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Deploying my application at the root in Tomcat
...couple of options:
Remove the out-of-the-box ROOT/ directory from tomcat and rename your war file to ROOT.war before deploying it.
Deploy your war as (from your example) war_name.war and configure the context root in conf/server.xml to use your war file :
<Context path="" docBase="war_name" de...
Always pass weak reference of self into block in ARC?
...am a little confused about block usage in Objective-C. I currently use ARC and I have quite a lot of blocks in my app, currently always referring to self instead of its weak reference. May that be the cause of these blocks retaining self and keeping it from being dealloced ? The question is, sho...
filters on ng-model in an input
I have a text input and I don't want to allow users to use spaces, and everything typed will be turned into lowercase.
8 An...
On design patterns: When should I use the singleton?
...ptable" reasons to use a Singleton.
One reason that tends to come up over and over again on the internets is that of a "logging" class (which you mentioned). In this case, a Singleton can be used instead of a single instance of a class because a logging class usually needs to be used over and over ...
Evaluating a mathematical expression in a string
...ppend(toks[0])
def pushUMinus(self, strg, loc, toks):
if toks and toks[0] == '-':
self.exprStack.append('unary -')
def __init__(self):
"""
expop :: '^'
multop :: '*' | '/'
addop :: '+' | '-'
integer :: ['+' | '-'] '0'..'9'+
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MongoDB logging all queries
...d parameter to -1, like db.setProfilingLevel(2,-1)
– andresigualada
Apr 12 '16 at 10:42
4
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Cast Double to Integer in Java
...ger, so the cast won't work. Note the difference between the Double class and the double primitive. Also note that a Double is a Number, so it has the method intValue, which you can use to get the value as a primitive int.
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Why can't C++ be parsed with a LR(1) parser?
I was reading about parsers and parser generators and found this statement in wikipedia's LR parsing -page:
6 Answers
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Convert a binary NodeJS Buffer to JavaScript ArrayBuffer
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Instances of Buffer are also instances of Uint8Array in node.js 4.x and higher. Thus, the most efficient solution is to access the buf.buffer property directly, as per https://stackoverflow.com/a/31394257/1375574. The Buffer constructor also takes an ArrayBufferView argument if you need to ...