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How to get the last N rows of a pandas DataFrame?
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mysql_fetch_array()/mysql_fetch_assoc()/mysql_fetch_row()/mysql_num_rows etc… expects parameter 1 to
I am trying to select data from a MySQL table, but I get one of the following error messages:
31 Answers
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How to programmatically get iOS status bar height
...als 20.0f points except following cases:
status bar has been hidden with setStatusBarHidden:withAnimation: method and its height equals 0.0f points;
as @Anton here pointed out, during an incoming call outside of Phone application or during sound recording session status bar height equals 40.0f poi...
What are metaclasses in Python?
...anything that subclasses or uses it.
Metaclasses in Python 3
The syntax to set the metaclass has been changed in Python 3:
class Foo(object, metaclass=something):
...
i.e. the __metaclass__ attribute is no longer used, in favor of a keyword argument in the list of base classes.
The behavior of ...
How to create an infinite loop in Windows batch file?
...
Here is an example of using the loop:
echo off
cls
:begin
set /P M=Input text to encode md5, press ENTER to exit:
if %M%==%M1% goto end
echo.|set /p ="%M%" | openssl md5
set M1=%M%
Goto begin
This is the simple batch i use when i need to encrypt any message into md5 hash on Win...
Concatenating two one-dimensional NumPy arrays
...s created with perfplot:
import numpy
import perfplot
perfplot.show(
setup=lambda n: numpy.random.rand(n),
kernels=[
lambda a: numpy.r_[a, a],
lambda a: numpy.stack([a, a]).reshape(-1),
lambda a: numpy.hstack([a, a]),
lambda a: numpy.concatenate([a, a]),
...
How do I get the currently displayed fragment?
I am playing with fragments in Android.
50 Answers
50
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How to print a number with commas as thousands separators in JavaScript
...as for numbers
number.toLocaleString(); // "1,234,567,890"
// With custom settings, forcing a "US" locale to guarantee commas in output
var number2 = 1234.56789; // floating point example
number2.toLocaleString('en-US', {maximumFractionDigits:2}) // "1,234.57"
NumberFormat
var nf = new Intl.Numbe...
“var” or no “var” in JavaScript's “for-in” loop?
...
The first version:
for (var x in set) {
...
}
declares a local variable called x. The second version:
for (x in set) {
...
}
does not.
If x is already a local variable (i.e. you have a var x; or var x = ...; somewhere earlier in your current sc...
Python SQL query string formatting
I'm trying to find the best way to format an sql query string. When I'm debugging
my application I'd like to log to file all the sql query strings, and it is
important that the string is properly formated.
...