大约有 40,000 项符合查询结果（耗时：0.0356秒） [XML]
Removing multiple keys from a dictionary safely
...
Why not like this:
entries = ('a', 'b', 'c')
the_dict = {'b': 'foo'}
def entries_to_remove(entries, the_dict):
for key in entries:
if key in the_dict:
del the_dict[key]
A more compact version was provided by mattbornski using dict.pop()
...
Declaration/definition of variables locations in ObjectiveC?
Ever since starting to work on iOS apps and objective C I've been really puzzled by the different locations where one could be declaring and defining variables. On one hand we have the traditional C approach, on the other we have the new ObjectiveC directives that add OO on top of that. Could you fo...
Static methods in Python?
Is it possible to have static methods in Python which I could call without initializing a class, like:
10 Answers
...
URL Encoding using C#
...file name) may be constructed using Uri.EscapeDataString(fileOrFolderName) allowing all non Uri compatible character (spaces, unicode ...). For example to allow any character in filename, use: req =(FtpWebRequest)WebRequest.Create(new Uri(path + "/" + Uri.EscapeDataString(filename))); Using...
代码块超过1.2w编译apk报错问题 - App Inventor 2 中文网 - 清泛IT社区，为创新赋能！
...ng.api.ApiProxy$RequestTooLargeException: The request to API call datastore_v3.Put() was too large.
at com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java:416)
at com.google.gwt.user.server.rpc.RPC.invokeAnd...
How to open every file in a folder?
...
Os
You can list all files in the current directory using os.listdir:
import os
for filename in os.listdir(os.getcwd()):
with open(os.path.join(os.cwd(), filename), 'r') as f: # open in readonly mode
# do your stuff
Glob
Or you c...
Python: One Try Multiple Except
...n) as e:
handle_either_of_3rd_4th_or_5th()
except Exception:
handle_all_other_exceptions()
See: http://docs.python.org/tutorial/errors.html
The "as" keyword is used to assign the error to a variable so that the error can be investigated more thoroughly later on in the code. Also note that...
More elegant way of declaring multiple variables at the same time
...variables with Boolean values is the best way to write your routine (especially if they really have one-letter names :)
Depending on what you're doing, it may make sense to use a dictionary instead. For example, if you want to set up Boolean preset values for a set of one-letter flags, you could d...
How to check if object (variable) is defined in R?
...
heh. Happens to me all the time when I am testing out examples before posting, Gavin or Josh have already answered it.
– Maiasaura
Feb 20 '12 at 22:17
...
/usr/lib/libstdc++.so.6: version `GLIBCXX_3.4.15' not found
...
I'm compiling gcc 4.6 from source, and apparently
sudo make install
didn't catch this one. I dug around and found
gcc/trunk/x86_64-unknown-linux-gnu/libstdc++-v3/src/.libs/libstdc++.so.6.0.15
I copied it in to /usr/lib and redirected libstdc++.so.6 to point to the new one, and now e...