大约有 40,000 项符合查询结果（耗时：0.0293秒） [XML]
undefined reference to boost::system::system_category() when compiling
...raries. I have the 1.46-dev Boost libraries from the Ubuntu Repository installed, but I get an error when compiling the program.
...
Use cases for the 'setdefault' dict method
...e case: Grouping items (in unsorted data, else use itertools.groupby)
# really verbose
new = {}
for (key, value) in data:
if key in new:
new[key].append( value )
else:
new[key] = [value]
# easy with setdefault
new = {}
for (key, value) in data:
group = new.setdefault(k...
Timeout on a function call
I'm calling a function in Python which I know may stall and force me to restart the script.
18 Answers
...
When is “i += x” different from “i = i + x” in Python?
...
This depends entirely on the object i.
+= calls the __iadd__ method (if it exists -- falling back on __add__ if it doesn't exist) whereas + calls the __add__ method1 or the __radd__ method in a few cases2.
From an API perspective, __iadd__ is supposed to be used fo...
How to convert vector to array
...making a pointer that points to the actual array the vector is using internally. If you want to copy GMan's answer explains how
– Michael Mrozek
May 27 '10 at 17:22
4
...
Programmatically Request Access to Contacts
...ss to the address book must be granted before it can be access programmatically. Here is what I ended up doing.
#import <AddressBookUI/AddressBookUI.h>
// Request authorization to Address Book
ABAddressBookRef addressBookRef = ABAddressBookCreateWithOptions(NULL, NULL);
if (ABAddress...
Why do we always prefer using parameters in SQL statements?
...uld be
SELECT empSalary from employee where salary = 0 or 1=1
whereby all empSalaries would be returned.
Further, a user could perform far worse commands against your database, including deleting it If they wrote 0; Drop Table employee:
SELECT empSalary from employee where salary = 0; Drop Ta...
How do you query for “is not null” in Mongo?
...
This will return all documents with a key called "IMAGE URL", but they may still have a null value.
db.mycollection.find({"IMAGE URL":{$exists:true}});
This will return all documents with both a key called "IMAGE URL" and a non-null value.
d...
jumpserver-华为云免费堡垒机解决方案 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...d/bak/
wget http://mirrors.163.com/.help/CentOS6-Base-163.repo
yum clean all
yum makecache
如果是REHL需要修改
1.删除redhat原有的yum
rpm -aq|grep yum|xargs rpm -e --nodeps
2.下载yum安装文件
wget http://mirrors.163.com/centos/6.7/os/x86_64/Packages/yum-3.2.29-69.el6.ce...
python exception message capturing
...work, I get syntax error, what is the proper way of doing this for logging all kind of exceptions to a file
11 Answers
...