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Count how many records are in a CSV Python?
...aranteed to be a fixed size, so the only way to count them is to read them all.
– Martijn Pieters♦
Apr 19 '13 at 15:55
1
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Collection that allows only unique items in .NET?
...
If all you need is to ensure uniqueness of elements, then HashSet is what you need.
What do you mean when you say "just a set implementation"? A set is (by definition) a collection of unique elements that doesn't save element ...
[精华] VC中BSTR、Char和CString类型的转换 - C/C++ - 清泛网 - 专注C/C++及内核技术
..."This is a test";
或在已定义Unicode应的用程序中
TCHAR * p = _T("This is a test");
或
LPTSTR p = _T("This is a test");
CString theString = chArray;
theString.format(_T("%s"), chArray);
theString = p;
2、CString转换成char*
若将CString类转换成char*(LPSTR)类型，常...
How do I write the 'cd' command in a makefile?
...
It is actually executing the command, changing the directory to some_directory, however, this is performed in a sub-process shell, and affects neither make nor the shell you're working from.
If you're looking to perform more tasks wit...
How do I get logs/details of ansible-playbook module executions?
...dd the following lines to your ansible configuration file:
[defaults]
log_path=/path/to/logfile
Ansible will look in several places for the config file:
ansible.cfg in the current directory where you ran ansible-playbook
~/.ansible.cfg
/etc/ansible/ansible.cfg
...
SQL Server Insert if not exists
...ode
BEGIN
INSERT INTO EmailsRecebidos (De, Assunto, Data)
VALUES (@_DE, @_ASSUNTO, @_DATA)
WHERE NOT EXISTS ( SELECT * FROM EmailsRecebidos
WHERE De = @_DE
AND Assunto = @_ASSUNTO
AND Data = @_DATA);
END
replace with
BEGIN
I...
What is a memory fence?
...ead/writes occur in the order you expect. For example a 'full fence' means all read/writes before the fence are comitted before those after the fence.
Note memory fences are a hardware concept. In higher level languages we are used to dealing with mutexes and semaphores - these may well be implemen...
How is the undo tree used in Vim?
...
See also :h undo-redo, which lists all the commands and their usage.
There are two ways to traverse the undo tree. One is to go "back in time". g+ and g- will traverse all of the nodes in the tree in chronological or reverse-chronological order (which can...
What does character set and collation mean exactly?
...a symbol, the number 0 is the
encoding for 'A', and the combination
of all four letters and their
encodings is a character set.
Now, suppose that we want to compare
two string values, 'A' and 'B'. The
simplest way to do this is to look at
the encodings: 0 for 'A' and 1 for
'B'. Be...
How can you profile a Python script?
...
Python includes a profiler called cProfile. It not only gives the total running time, but also times each function separately, and tells you how many times each function was called, making it easy to determine where you should make optimizations.
You c...