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How do I find out if first character of a string is a number?
...s, you must first be sure that the string isn't empty. If it is, charAt(0) and substring(0, 1) will throw a StringIndexOutOfBoundsException. startsWith does not have this problem.
To make the entire condition one line and avoid length checks, you can alter the regexes to the following:
s.matches("...
What is the most efficient way of finding all the factors of a number in Python?
...
The reduce(list.__add__, ...) is taking the little lists of [fac1, fac2] and joining them together in one long list.
The [i, n/i] for i in range(1, int(sqrt(n)) + 1) if n % i == 0 returns a pair of factors if the remainder when you divide n by the smaller one is zero (it doesn't need to check the...
Can't connect to local MySQL server through socket '/tmp/mysql.sock
...for me. However, if this doesnt work then make sure that mysqld is running and try connecting.
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Defining a percentage width for a LinearLayout? [duplicate]
...0%) for a LinearLayout that contains some buttons, so that I can center it and so that the child buttons can fill_parent. Here's a picture showing what I mean:
...
How do I keep track of pip-installed packages in an Anaconda (Conda) environment?
I've installed and have been using the Anaconda Python distribution, and I have started using the Anaconda (Conda) environment. I can use the standard conda install... command to put packages from the distribution into my environments, but to use anything outside (i.e. Flask-WTF, flask-sqlalchem...
How to deal with SettingWithCopyWarning in Pandas?
I just upgraded my Pandas from 0.11 to 0.13.0rc1. Now, the application is popping out many new warnings. One of them like this:
...
How do I upload a file with metadata using a REST web service?
...ude": 12.59817,
"Longitude": 52.12873
}
To create the metadata entry and return a response like:
201 Created
Location: http://server/data/media/21323
{
"Name": "Test",
"Latitude": 12.59817,
"Longitude": 52.12873,
"ContentUrl": "http://server/data/media/21323/content"
}
The c...
Is < faster than
...n two machine instructions:
A test or cmp instruction, which sets EFLAGS
And a Jcc (jump) instruction, depending on the comparison type (and code layout):
jne - Jump if not equal --> ZF = 0
jz - Jump if zero (equal) --> ZF = 1
jg - Jump if greater --> ZF = 0 and SF = OF
(etc...)
Exa...
'float' vs. 'double' precision
... in C use IEEE 754 encoding.
This type of encoding uses a sign, a significand, and an exponent.
Because of this encoding, many numbers will have small changes to allow them to be stored.
Also, the number of significant digits can change slightly since it is a binary representation, not a decimal ...
How do I get the path and name of the file that is currently executing?
...vide an example? I've answered similar question using inspect.getabsfile() and it worked for all cases that I've tried.
– jfs
Apr 5 '14 at 17:04
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