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Is there a 'foreach' function in Python 3?
...nt:
// PHP:
foreach ($array as $val) {
print($val);
}
// C#
foreach (String val in array) {
console.writeline(val);
}
// Python
for val in array:
print(val)
So, yes, there is a "foreach" in python. It's called "for".
What you're describing is an "array map" function. This could be ...
How do I get the number of elements in a list?
...e number of items) of an object. The argument may be a sequence (such as a string, bytes, tuple, list, or range) or
a collection (such as a dictionary, set, or frozen set).
len is implemented with __len__, from the data model docs:
object.__len__(self)
Called to implement the built-in funct...
Java regex email
...\.[A-Z]{2,6}$", Pattern.CASE_INSENSITIVE);
public static boolean validate(String emailStr) {
Matcher matcher = VALID_EMAIL_ADDRESS_REGEX.matcher(emailStr);
return matcher.find();
}
Works fairly reliably.
s...
Regex Named Groups in Java
...p "name"
${name} to reference to captured group in Matcher's replacement string
Matcher.group(String name) to return the captured input subsequence by the given "named group".
Other alternatives for pre-Java 7 were:
Google named-regex (see John Hardy's answer)
Gábor Lipták mentions (N...
Flask-SQLalchemy update a row's information
...:
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(80), unique=True)
data = db.Column(db.PickleType())
def __init__(self, name, data):
self.name = name
self.data = data
def __repr__(self):
return '<User %r>' % self.username
...
Passing references to pointers in C++
...
Your function expects a reference to an actual string pointer in the calling scope, not an anonymous string pointer. Thus:
string s;
string* _s = &s;
myfunc(_s);
should compile just fine.
However, this is only useful if you intend to modify the pointer you pass to...
IN clause and placeholders
...
A string of the form "?, ?, ..., ?" can be a dynamically created string and safely put into the original SQL query (because it is a restricted form that does not contain external data) and then the placeholders can be used as n...
Error to install Nokogiri on OSX 10.9 Maverick?
...gdb -Wextra -Wno-unused-parameter -Wno-parentheses -Wpointer-arith -Wwrite-strings -Wno-missing-field-initializers -Wshorten-64-to-32 -Wno-long-long -fno-common -pipe -g -DXP_UNIX -O3 -Wall -Wcast-qual -Wwrite-strings -Wconversion -Wmissing-noreturn -Winline -DNOKOGIRI_USE_PACKAGED_LIBRARIES -DNOK...
How to use Global Variables in C#?
... public const Int32 BUFFER_SIZE = 512; // Unmodifiable
public static String FILE_NAME = "Output.txt"; // Modifiable
public static readonly String CODE_PREFIX = "US-"; // Unmodifiable
}
You can then retrieve the defined values anywhere in your code (provided it's part of the same namespac...
How does one write code that best utilizes the CPU cache to improve performance?
...rewriting techniques known as tiling or blocking all strive to avoid those extra memory fetches.
While there are some rules of thumb for this rewrite exercise, you typically have to carefully consider loop carried data dependencies, to ensure that you don't affect the semantics of the program.
The...