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Python __str__ and lists
In Java, if I call List.toString(), it will automatically call the toString() method on each object inside the List. For example, if my list contains objects o1, o2, and o3, list.toString() would look something like this:
...
Repeat string to certain length
... that need to be // in Python 3? Or dropping the +1 and using an explicit call to a ceiling function would suffice. Also, a note: the string generated actually has an extra repetition when it divides evenly; the extra gets cut off by the splice. That confused me at first.
– jpm...
SQLAlchemy: cascade delete
...use that is where you defined your relationship (it doesn't care that you called it "Child" of course).
If you define the relationship on the Parent class instead, it will work:
children = relationship("Child", cascade="all,delete", backref="parent")
(note "Child" as a string: this is allowed wh...
C++0x has no semaphores? How to synchronize threads?
...ck Overflow regarding the use of semaphores. I use them (posix semaphores) all the time to let a thread wait for some event in another thread:
...
Boost.Asio的简单使用(Timer,Thread,Io_service类) - C/C++ - 清泛网 - 专注C/C++及内核技术
... asio::write(socket, asio::buffer(message),
asio::transfer_all(), asio::ignore_error());
}
}
最后处理异常
catch (std::exception& e)
{
std::cerr << e.what() << std::endl;
}
return 0;
运行示例:运行服务器,然后运行上一节的客户端,在win...
Virtual Memory Usage from Java under Linux, too much memory used
... a long-standing complaint with Java, but it's largely meaningless, and usually based on looking at the wrong information. The usual phrasing is something like "Hello World on Java takes 10 megabytes! Why does it need that?" Well, here's a way to make Hello World on a 64-bit JVM claim to take over 4...
How to implement the --verbose or -v option into a script?
...
def verboseprint(*args):
# Print each argument separately so caller doesn't need to
# stuff everything to be printed into a single string
for arg in args:
print arg,
print
else:
verboseprint = lambda *a: None # do-nothing function
(Yes, y...
Semantic Issue: Property's synthesized getter follows Cocoa naming convention for returning 'owned'
... the memory management rules for declared properties, too — more specifically, for declared properties’ accessors:
You take ownership of an object if you create it using a method whose name begins with “alloc”, “new”, “copy”, or “mutableCopy”.
A property named newTitle, whe...
Rounding up to next power of 2
...mon: it's the portable solution. There's no common efficient algorithm for all architectures
– phuclv
Dec 6 '13 at 9:27
5
...
Meaning of @classmethod and @staticmethod for beginner? [duplicate]
...ect as the first parameter, whereas staticmethod can have no parameters at all.
Example
class Date(object):
def __init__(self, day=0, month=0, year=0):
self.day = day
self.month = month
self.year = year
@classmethod
def from_string(cls, date_as_string):
...