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Find which version of package is installed with pip
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As of pip 1.3, there is a pip show command.
$ pip show Jinja2
---
Name: Jinja2
Version: 2.7.3
Location: /path/to/virtualenv/lib/python2.7/site-packages
Requires: markupsafe
In older versions, pip freeze and grep should do the job nicely.
$ pip freeze | grep Ji...
SyntaxError: Use of const in strict mode
I'm working with node.js, and in one of my js files I'm using const in "strict mode" . When trying to run it, I'm getting an error:
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Return type of '?:' (ternary conditional operator)
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Expressions don't have return types, they have a type and - as it's known in the latest C++ standard - a value category.
A conditional expression can be an lvalue or an rvalue. This is its value category. (This is somewhat of a simplification, in C++11 we have lvalues, xvalues a...
How to find duplicates in 2 columns not 1
...composite key between the two fields. This will require a unique stone_id and upcharge_title for each row.
As far as finding the existing duplicates try this:
select stone_id,
upcharge_title,
count(*)
from your_table
group by stone_id,
upcharge_title
having coun...
How can I permanently enable line numbers in IntelliJ?
...log is slightly different, a General submenu has been added between Editor and Appearance as shown below
IntelliJ 8.1.2 - 13.X
From IntelliJ 8.1.2 onwards, this option is in File | Settings1. Within the IDE Settings section of that dialog, you'll find it under Editor | Appearance.
On a Mac, th...
Double vs. BigDecimal?
I have to calculate some floating point variables and my colleague suggest me to use BigDecimal instead of double since it will be more precise. But I want to know what it is and how to make most out of BigDecimal ?
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What are dictionary view objects?
...sentially what their name says: views are simply like a window on the keys and values (or items) of a dictionary. Here is an excerpt from the official documentation for Python 3:
>>> dishes = {'eggs': 2, 'sausage': 1, 'bacon': 1, 'spam': 500}
>>> keys = dishes.keys()
>>>...
How can I delete a query string parameter in JavaScript?
... better way to delete a parameter from a query string in a URL string in standard JavaScript other than by using a regular expression?
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Named string formatting in C#
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There is no built-in method for handling this.
Here's one method
string myString = "{foo} is {bar} and {yadi} is {yada}".Inject(o);
Here's another
Status.Text = "{UserName} last logged in at {LastLoginDate}".FormatWith(user);
A third improved method p...
What is the difference between mutex and critical section?
... between the two of them. On my system for 1,000,000 uncontended acquires and releases, a mutex takes over one second. A critical section takes ~50 ms for 1,000,000 acquires.
Here's the test code, I ran this and got similar results if mutex is first or second, so we aren't seeing any other effect...