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How do I get the row count of a pandas DataFrame?
...eturn non-NaN counts for each column:
df.count()
A 5
B 3
dtype: int64
For Series, use Series.count to similar effect:
s.count()
# 3
Group-wise Row Count: GroupBy.size
For DataFrames, use DataFrameGroupBy.size to count the number of rows per group.
df.groupby('A').size()
A
a 2
b ...
Java equivalent of unsigned long long?
In C++, I enjoyed having access to a 64 bit unsigned integer, via unsigned long long int , or via uint64_t . Now, in Java longs are 64 bits, I know. However, they are signed.
...
How to assign colors to categorical variables in ggplot2 that have stable mapping?
...
[11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C
attached base packages:
[1] methods stats graphics grDevices utils datasets base
other attached packages:
[1] ggplot2_0.9.3.1
loaded via a namespace (and not attached):
[1] colorspace_1.2-4 dichromat_2.0-0 dig...
Convert integer to hexadecimal and back again
...the hex equivalent. HEX is not a terrible solution for this problem, but a base64 of the four bytes in the int would be even shorter (and you could trim the padding)
– James Hart
Aug 16 '11 at 21:08
...
Can't open config file: /usr/local/ssl/openssl.cnf on Windows [duplicate]
I have installed OpenSSL 64. I want to use a certificate for my nodejs https server. I ran the following command:
7 Answers...
Lombok is not generating getter and setter
I just tried to send a Maven-based project to another computer and HORROR,
red markers everywhere!!
20 Answers
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Why does installing Nokogiri on Mac OS fail with libiconv is missing?
...or unsupported file format which is not the architecture being linked (x86_64) for architecture x86_64
Uhh, what? After a lot of googling, I came across this miracle post: http://www.refresherate.com/2010/01/08/fixing-ld-warning-in-usrlocalliblibz-dylib-file-is-not-of-required-architecture/
Appar...
Detect application heap size in Android
... to 32:
maxMemory: 33554432
getMemoryClass: 32
With VM Heap Size set to 64:
maxMemory: 67108864
getMemoryClass: 32
In addition to the above, I tested on a Novo7 Paladin tablet running Ice Cream Sandwich.
This was essentially a stock version of ICS, except that I've rooted the tablet through...
How do I make a textbox that only accepts numbers?
...
protected override void OnKeyPress(KeyPressEventArgs e)
{
base.OnKeyPress(e);
NumberFormatInfo fi = CultureInfo.CurrentCulture.NumberFormat;
string c = e.KeyChar.ToString();
if (char.IsDigit(c, 0))
return;
if ((SelectionStart == 0) &...
What is the MySQL VARCHAR max size?
...
As per the online docs, there is a 64K row limit and you can work out the row size by using:
row length = 1
+ (sum of column lengths)
+ (number of NULL columns + delete_flag + 7)/8
+ (number of variable-length columns)
...