大约有 7,000 项符合查询结果（耗时：0.0360秒） [XML]
Error handling in Bash
...rror ${LINENO}' ERR
...then, whenever you create a temporary file:
temp_foo="$(mktemp -t foobar.XXXXXX)"
tempfiles+=( "$temp_foo" )
and $temp_foo will be deleted on exit, and the current line number will be printed. (set -e will likewise give you exit-on-error behavior, though it comes with ser...
How to get a variable value if variable name is stored as string?
...
X=foo
Y=X
eval "Z=\$$Y"
sets Z to "foo"
Take care using eval since this may allow accidential excution of code through values in ${Y}. This may cause harm through code injection.
For example
Y="\`touch /tmp/eval-is-evil\`"...
How to split a string in shell and get the last field
...
You can use string operators:
$ foo=1:2:3:4:5
$ echo ${foo##*:}
5
This trims everything from the front until a ':', greedily.
${foo <-- from variable foo
## <-- greedy front trim
* <-- matches anything
: <-- until the last ':'
...
Python argparse mutual exclusive group
...arser
parser = argparse.ArgumentParser(prog='PROG')
parser.add_argument('--foo', action='store_true', help='help for foo arg.')
subparsers = parser.add_subparsers(help='help for subcommand')
# create the parser for the "command_1" command
parser_a = subparsers.add_parser('command_1', help='command_...
Why are Python's 'private' methods not actually private?
... prevent deliberate access from outside.
For example:
>>> class Foo(object):
... def __init__(self):
... self.__baz = 42
... def foo(self):
... print self.__baz
...
>>> class Bar(Foo):
... def __init__(self):
... super(Bar, self).__init__(...
Pandas: Setting no. of max rows
...hon.display import display
import numpy as np
import pandas as pd
n = 100
foo = pd.DataFrame(index=range(n))
foo['floats'] = np.random.randn(n)
with pd.option_context("display.max_rows", foo.shape[0]):
display(foo)
pandas.option_context is available since pandas 0.13.1 (pandas 0.13.1 release...
How to do multiple arguments to map function where one remains the same in python?
...): \\ return '.'.join([x,y,z]) and then: list(map(f, list('abc'), repeat('foo'), list('defgh'))) returns ['a.foo.d', 'b.foo.e', 'c.foo.f'].
– Pierre D
May 13 '16 at 21:23
...
What does %5B and %5D in POST requests stand for?
...
As per this answer over here: str='foo%20%5B12%5D' encodes foo [12]:
%20 is space
%5B is '['
and %5D is ']'
This is called percent encoding and is used in encoding special characters in the url parameter values.
EDIT By the way as I was reading https://dev...
An example of how to use getopts in bash
...script.sh [-s <45|90>] [-p <string>]
$ ./myscript.sh -s 10 -p foo
Usage: ./myscript.sh [-s <45|90>] [-p <string>]
$ ./myscript.sh -s 45 -p foo
s = 45
p = foo
$ ./myscript.sh -s 90 -p bar
s = 90
p = bar
...
ASP.Net error: “The type 'foo' exists in both ”temp1.dll“ and ”temp2.dll"
When running a web application project, at seemingly random times a page may fail with a CS0433 error: type exists in multiple DLL's. The DLL's are all generated DLL's residing in the "Temporary ASP.NET Files" directory.
...