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Overloading member access operators ->, .*
...e first part of what -> does).
The C++ -> operator is basically the union of two steps and this is clear if you think that x->y is equivalent to (*x).y. C++ allows you to customize what to do with the (*x) part when x is an instance of your class.
The semantic for -> overloading is som...
How to perform OR condition in django queryset?
...
Because QuerySets implement the Python __or__ operator (|), or union, it just works. As you'd expect, the | binary operator returns a QuerySet so order_by(), .distinct(), and other queryset filters can be tacked on to the end.
combined_queryset = User.objects.filter(income__gte=5000) | ...
Network tools that simulate slow network connection [closed]
...e a public internet service on coffee shop wifi: sudo tc qdisc add dev lo root netem delay 500ms
– Sam Stokes
May 12 '10 at 21:21
7
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How do I make a Git commit in the past?
... your new commit. If you actually want your new file to be added via a new root commit (no parents), then you need something a bit different:
B---C---o---o---o master
git checkout master
git checkout --orphan new-root
git rm -rf .
git add path/to/file
GIT_AUTHOR_DATE='whenever' git commit
git ch...
What is the difference between a cer, pvk, and pfx file?
... of cryptographic information, including certificates, certificate chains, root authority certificates, and private keys. Its contents can be cryptographically protected (with passwords) to keep private keys private and preserve the integrity of root certificates.
Windows uses .pvk for a private ke...
How to merge dictionaries of dictionaries?
... generators:
def mergedicts(dict1, dict2):
for k in set(dict1.keys()).union(dict2.keys()):
if k in dict1 and k in dict2:
if isinstance(dict1[k], dict) and isinstance(dict2[k], dict):
yield (k, dict(mergedicts(dict1[k], dict2[k])))
else:
...
Using scp to copy a file to Amazon EC2 instance?
...'t know if you're joking or not... but :/ would try copy the folder to the root of the system, which would give permission errors on all machines without running sudo (or as root).
– Dobz
Jul 29 '14 at 15:17
...
How does one parse XML files? [closed]
... specific element, you can access child elements with the indexer: xmlDoc["Root"], and these can be chained: xmlDoc["Root"]["Folder"]["Item"] to dig down the hierarchy (although it's sensible to validate that these elements actually exist)
– Jason Williams
Mar ...
How to do an INNER JOIN on multiple columns
...ave an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'INNER_JOIN airports to_port ON (to_port.code = flights.tairport) WHERE ' at line 7
– Kiril
Mar 2 '10 at 21:26
...
PostgreSQL error: Fatal: role “username” does not exist
...TE USER username;
eg. CREATE USER demo;
Assign privilege to user
GRANT ROOT TO username;
And then enable login that user, so you can run e.g.: psql template1, from normal $ terminal:
ALTER ROLE username WITH LOGIN;
s...