大约有 40,000 项符合查询结果（耗时：0.0608秒） [XML]
Pandas - How to flatten a hierarchical index in columns
..., but leaves behind column names which are difficult to access programmatically and are not queriable
– dmeu
Jun 29 '17 at 8:53
1
...
How can I check if a string represents an int, without using try/except?
...
If you're really just annoyed at using try/excepts all over the place, please just write a helper function:
def RepresentsInt(s):
try:
int(s)
return True
except ValueError:
return False
>>> pri...
Does reading an entire file leave the file handle open?
...hat on the particular Python implementation.
To understand what this is all about, pay particular attention to the actual file object. In your code, that object is mentioned only once, in an expression, and becomes inaccessible immediately after the read() call returns.
This means that the file...
Git's famous “ERROR: Permission to .git denied to user”
...means the old date items and incorrect email or username. You can sort the table by Date Modified.
– Alice Chan
Nov 22 '17 at 10:10
...
What is the point of Lookup?
...
@KyleBaran Lookup<,> is simply an immutable collection (with no Add method for eg) which has a limited use. Furthermore, its not a general purpose collection in the sense that if you do lookup on a nonexistent key you get an empty sequence rather than an exceptio...
Relationship between hashCode and equals method in Java [duplicate]
...), for instance keys in a HashMap.
As its name implies, it relies on hash tables, and hash buckets are a function of the object's .hashCode().
If you have two objects which are .equals(), but have different hash codes, you lose!
The part of the contract here which is important is: objects which a...
Is there a “standard” format for command line/shell help text?
... case it is not very specific. You probably can't go wrong with printing a table showing the short and long options and a succinct description. Try to get the spacing between all arguments right for readability. You probably want to provide a man page (and possibly an info manual) for your tool to p...
Do I need to explicitly call the base virtual destructor?
...the destructor again as virtual on the inheriting class, but do I need to call the base destructor?
7 Answers
...
PHP equivalent of .NET/Java's toString()
...
@MarkAmery He gave an answer that implicitly calls the __toString() "Magic Method", but didn't mention that at all. The user asked for an answer that was like the Java toString() method, and in PHP, that's the __toString() function.
– Supuhstar
...
Error handling in Bash
...kens code's predictability and portability).
You can either let the trap call error for you (in which case it uses the default exit code of 1 and no message) or call it yourself and provide explicit values; for instance:
error ${LINENO} "the foobar failed" 2
will exit with status 2, and give an ...