大约有 40,000 项符合查询结果（耗时：0.0247秒） [XML]
Importing a CSV file into a sqlite3 database table using Python
...csv, sqlite3
con = sqlite3.connect(":memory:") # change to 'sqlite:///your_filename.db'
cur = con.cursor()
cur.execute("CREATE TABLE t (col1, col2);") # use your column names here
with open('data.csv','r') as fin: # `with` statement available in 2.5+
# csv.DictReader uses first line in file fo...
How do you run a Python script as a service in Windows?
...mport socket
class AppServerSvc (win32serviceutil.ServiceFramework):
_svc_name_ = "TestService"
_svc_display_name_ = "Test Service"
def __init__(self,args):
win32serviceutil.ServiceFramework.__init__(self,args)
self.hWaitStop = win32event.CreateEvent(None,0,0,None)
...
How to encrypt/decrypt data in php?
...er generator. The following example would be recommended (>= 5.3):
$key_size = 32; // 256 bits
$encryption_key = openssl_random_pseudo_bytes($key_size, $strong);
// $strong will be true if the key is crypto safe
This can be done once or multiple times (if you wish to create a chain of encrypti...
Creating a singleton in Python
... a base class. Here is a sample implementation:
class Singleton(type):
_instances = {}
def __call__(cls, *args, **kwargs):
if cls not in cls._instances:
cls._instances[cls] = super(Singleton, cls).__call__(*args, **kwargs)
return cls._instances[cls]
class...
What is the maximum recursion depth in Python, and how to increase it?
...mple context manager like this:
import sys
class recursionlimit:
def __init__(self, limit):
self.limit = limit
self.old_limit = sys.getrecursionlimit()
def __enter__(self):
sys.setrecursionlimit(self.limit)
def __exit__(self, type, value, tb):
sys.setr...
Rank function in MySQL
...ption is to use a ranking variable, such as the following:
SELECT first_name,
age,
gender,
@curRank := @curRank + 1 AS rank
FROM person p, (SELECT @curRank := 0) r
ORDER BY age;
The (SELECT @curRank := 0) part allows the variable initialization without requi...
Log exception with traceback
...g with the trace information, prepended with a message.
import logging
LOG_FILENAME = '/tmp/logging_example.out'
logging.basicConfig(filename=LOG_FILENAME, level=logging.DEBUG)
logging.debug('This message should go to the log file')
try:
run_my_stuff()
except:
logging.exception('Got excep...
How to implement an STL-style iterator and avoid common pitfalls?
... void swap(iterator& lhs, iterator& rhs); //C++11 I think
};
input_iterator : public virtual iterator {
iterator operator++(int); //postfix increment
value_type operator*() const;
pointer operator->() const;
friend bool operator==(const iterator&, const iterator&)...
Any way to make a WPF textblock selectable?
...rWrapper(textContainer, tb, false);
IsReadOnlyProp.SetValue(editor._editor, true);
TextViewProp.SetValue(editor._editor, TextContainerTextViewProp.GetValue(textContainer));
return editor;
}
private readonly object _editor;
public TextEditorWrapper(object textCo...
Checking for empty queryset in Django
...is the code I refer to is only an example that it contains a line if not my_objects: to demonstrate that this is how they do it in the docs. All else is utterly irrelevant so I do not get your point. They could as well make a thousand queries and it would still be totally irrelevant as this is not t...