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In which scenario do I use a particular STL container?
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You now have unordered_map and unordered_set (and their multi variants) which are not in the flow chart but are good picks when you don't care about order but need to find elements by key. Their lookup is usually O(1) instead of O(log n).
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How can I get around MySQL Errcode 13 with SELECT INTO OUTFILE?
...essages when AppArmor blocks the writes/accesses. What you can do is edit /etc/apparmor.d/usr.sbin.mysqld and add /data/ and /data/* near the bottom like so:
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/usr/sbin/mysqld {
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/var/log/mysql/ r,
/var/log/mysql/* rw,
/var/run/mysqld/mysqld.pid w,
/var/run/my...
Android-java- How to sort a list of objects by a certain value within the object
... compare(EmployeeClass obj1, EmployeeClass obj2) {
// ## Ascending order
return obj1.firstName.compareToIgnoreCase(obj2.firstName); // To compare string values
// return Integer.valueOf(obj1.empId).compareTo(Integer.valueOf(obj2.empId)); // To compare integer values
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Assign pandas dataframe column dtypes
... I have 1000's of files from cisco logs that I need to parse manually.
In order to be flexible with fields and types I have successfully tested using StringIO + read_cvs which indeed does accept a dict for the dtype specification.
I usually get each of the files ( 5k-20k lines) into a buffer and ...
Linux日志管理Rsyslog入门 - C/C++ - 清泛网移动版 - 专注C/C++及内核技术
...的Linux缺省使用Syslog，其配置大致如下所示：
shell> cat /etc/syslog.conf
# Log all kernel messages to the console.
# Logging much else clutters up the screen.
# kern.* /dev/console
# Log anything (except mail) of level info or higher.
# Don't log private authentication mes...
Is it worth using Python's re.compile?
....compile. If we call it, we bypass the cache. It turns out to be about two orders of magnitude slower for a basic regular expression, such as r'\w+\s+([0-9_]+)\s+\w*'.
Here's my test:
#!/usr/bin/env python
import re
import time
def timed(func):
def wrapper(*args):
t = time.time()
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Using Linq to get the last N elements of a collection?
....Skip(Math.Max(0, collection.Count() - N));
This approach preserves item order without a dependency on any sorting, and has broad compatibility across several LINQ providers.
It is important to take care not to call Skip with a negative number. Some providers, such as the Entity Framework, will p...
SSL_connect returned=1 errno=0 state=SSLv3 read server certificate B: certificate verify failed
... that is trying to verify the SSL certification: SSL_CERT_FILE=/opt/local/etc/certs/cacert.pem rails generate jquery:install. In your case, you want to either set this as an environment variable somewhere the server picks it up or add something like ENV['SSL_CERT_FILE'] = /path/to/your/new/cacert.p...
Java: how to convert HashMap to array
...ray(); // returns an array of values
Edit
It should be noted that the ordering of both arrays may not be the same,
See oxbow_lakes answer for a better approach for iteration when the pair key/values are needed.
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Is there a way to 'uniq' by column?
...sort's manpage says: "-u, --unique with -c, check for strict ordering; without -c, output only the first of an equal run." So, it is indeed "the first occurrence of the duplicate before sorting."
– Geremia
Apr 15 '16 at 17:32
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