大约有 30,000 项符合查询结果（耗时：0.0337秒） [XML]
How to delete an item in a list if it exists?
...d catch relevant Exceptions:
try:
some_list.remove(thing)
except ValueError:
pass # or scream: thing not in some_list!
except AttributeError:
call_security("some_list not quacking like a list!")
Off course the second except clause in the example above is not only of questionable humor...
How do I get current date/time on the Windows command line in a suitable format for usage in a file/
...- snip -- snip ----------8<-------------
To get the code to work sans error msg's to stderr, I had to add the single quotes arount the variable assignments for %%a, %%b and %%c. My locale (PT) was causing errors at one stage in the looping/parsing where stuff like "set =20" was getting execute...
How do I plot in real-time in a while loop using matplotlib?
...ange(10):
y = np.random.random()
plt.scatter(i, y)
plt.pause(0.05)
plt.show()
Note some of the changes:
Call plt.pause(0.05) to both draw the new data and it runs the GUI's event loop (allowing for mouse interaction).
...
What would be C++ limitations compared C language? [closed]
...D_POSIX_C_SOURCE=200112L -Wall -Wextra -Wwrite-strings -Wredundant-decls -Werror -Isrc src/core/kin_object.c -c -o obj/kin_object.o | wc -l
In file included from src/core/kin_object.c:22:
src/core/kin_object.h:791:28: error: anonymous variadic macros were introduced in C99
In file included from src...
Entity framework linq query Include() multiple children entities
...xt node (NB: This does NOT work with AsNoTracking() - you'll get a runtime error):
var company = context.Companies
.Include(co =>
co.Employees
.Select(emp => emp.Employee_Car
.Select(ec => ec.Employee)
.Select(e...
Check if an apt-get package is installed and then install it if it's not on Linux
...s upon finding that the package is missing, such as simply exiting with an error code.
REQUIRED_PKG="some-package"
PKG_OK=$(dpkg-query -W --showformat='${Status}\n' $REQUIRED_PKG|grep "install ok installed")
echo Checking for $REQUIRED_PKG: $PKG_OK
if [ "" = "$PKG_OK" ]; then
echo "No $REQUIRED_P...
How to run a shell script in OS X by double-clicking?
... you'll see the following symptoms:
.command: Finder displays a misleading error message that suggests the problem can be fixed via File > Get Info, which is not true - use the chmod +x method suggested above.
no suffix:
with a shebang line (e.g., #!/bin/bash): behavior is as if the suffix wer...
How to enumerate a range of numbers starting at 1
... is straightforward to do in Python 2.6 or newer:
enumerate(range(2000, 2005), 1)
Python 2.5 and older do not support the start parameter so instead you could create two range objects and zip them:
r = xrange(2000, 2005)
r2 = xrange(1, len(r) + 1)
h = zip(r2, r)
print h
Result:
[(1, 2000), (...
linux: kill background task
... job. If a prefix matches more than one job, bash
reports an error. Using %?ce, on the other hand, refers to any job containing the string ce in its command line. If the
substring matches more than one job, bash reports an error. The symbols %% and %+ refer to the shell's n...
Explicitly select items from a list or tuple
... recent call last):
File "<stdin>", line 1, in <module>
IndexError: invalid index
>>> myBigList[[87, 342, 217, 998, 500]]
array([ 87, 342, 217, 998, 500])
>>> myBigList[numpy.array([87, 342, 217, 998, 500])]
array([ 87, 342, 217, 998, 500])
The tuple doesn't work th...