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How to take the first N items from a generator or list in Python? [duplicate]
...:step]
Slicing a generator
import itertools
top5 = itertools.islice(my_list, 5) # grab the first five elements
You can't slice a generator directly in Python. itertools.islice() will wrap an object in a new slicing generator using the syntax itertools.islice(generator, start, stop, step)
Rem...
Calling shell functions with xargs
...
Exporting the function should do it (untested):
export -f echo_var
seq -f "n%04g" 1 100 | xargs -n 1 -P 10 -I {} bash -c 'echo_var "$@"' _ {}
You can use the builtin printf instead of the external seq:
printf "n%04g\n" {1..100} | xargs -n 1 -P 10 -I {} bash -c 'echo_var "$@"' _ {}
...
Best algorithm for detecting cycles in a directed graph [closed]
...e following Wikipedia article:
http://en.wikipedia.org/wiki/Topological_sorting
has the pseudo-code for one algorithm, and a brief description of another from Tarjan. Both have O(|V| + |E|) time complexity.
share
...
How do I check if a string contains another string in Swift?
... and containsIgnoringCase for String
extension String {
func contains(_ find: String) -> Bool{
return self.range(of: find) != nil
}
func containsIgnoringCase(_ find: String) -> Bool{
return self.range(of: find, options: .caseInsensitive) != nil
}
}
Older Swift vers...
Python date string to date object
...<stdin>", line 1, in <module>
File "/usr/local/lib/python2.7/_strptime.py", line 308, in _strptime
format_regex = _TimeRE_cache.compile(format)
File "/usr/local/lib/python2.7/_strptime.py", line 265, in compile
return re_compile(self.pattern(format), IGNORECASE)
File "/usr/...
Why does Windows64 use a different calling convention from all other OSes on x86-64?
...ion encoding (the MOD R/M byte, see http://www.c-jump.com/CIS77/CPU/x86/X77_0060_mod_reg_r_m_byte.htm), register numbers 0...7 are - in that order - ?AX, ?CX, ?DX, ?BX, ?SP, ?BP, ?SI, ?DI.
Hence choosing A/C/D (regs 0..2) for return value and the first two arguments (which is the "classical" 32bit _...
Why is it string.join(list) instead of list.join(string)?
...ct, set), but the result and the "joiner" must be strings.
For example:
'_'.join(['welcome', 'to', 'stack', 'overflow'])
'_'.join(('welcome', 'to', 'stack', 'overflow'))
'welcome_to_stack_overflow'
Using something else than strings will raise the following error:
TypeError: sequence item 0...
How to write to Console.Out during execution of an MSTest test
...
internal class ConsoleRedirector : IDisposable
{
private StringWriter _consoleOutput = new StringWriter();
private TextWriter _originalConsoleOutput;
public ConsoleRedirector()
{
this._originalConsoleOutput = Console.Out;
Console.SetOut(_consoleOutput);
}
pub...
Adding a new value to an existing ENUM Type
...he new type.
-- 1. rename the enum type you want to change
alter type some_enum_type rename to _some_enum_type;
-- 2. create new type
create type some_enum_type as enum ('old', 'values', 'and', 'new', 'ones');
-- 3. rename column(s) which uses our enum type
alter table some_table rename column some...
Does Python optimize tail recursion?
...to find some clean solution, which is actually what
happens here...
class _RecursiveCall(Exception):
def __init__(self, *args):
self.args = args
def _recursiveCallback(*args):
raise _RecursiveCall(*args)
def bet0(func):
def wrapper(*args):
while True:
try:
...