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Booleans, conditional operators and autoboxing
...l() method affects the static typing of the expressions at compile time:
E1: `true ? returnsNull() : false` - boolean (auto-unboxing 2nd operand to boolean)
E2: `true ? null : false` - Boolean (autoboxing of 3rd operand to Boolean)
See Java Language Specification, section 15.25 Conditional Opera...
How do I retrieve the number of columns in a Pandas data frame?
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312
Like so:
import pandas as pd
df = pd.DataFrame({"pear": [1,2,3], "apple": [2,3,4], "orange": [...
How to jQuery clone() and change id?
I need to clone the id and then add a number after it like so id1 , id2 , etc. Everytime you hit clone you put the clone after the latest number of the id.
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Unique combination of all elements from two (or more) vectors
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141
this maybe what you are after
> expand.grid(a,b)
Var1 Var2
1 ABC 2012-05-01
2 ...
Disable intellij indexing on specific folder
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edited Jul 1 '11 at 19:34
answered Jun 30 '11 at 13:30
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Map function in MATLAB?
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133
The short answer: the built-in function arrayfun does exactly what your map function does for ...
How do I draw a grid onto a plot in Python?
...plot using pylab in Python and now I would like to superimpose a grid of 10x10 onto the scatter plot. How do I do that?
5...
How can I filter a Django query with a list of values?
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From the Django documentation:
Blog.objects.filter(pk__in=[1, 4, 7])
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How to get the last element of a slice?
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For just reading the last element of a slice:
sl[len(sl)-1]
For removing it:
sl = sl[:len(sl)-1]
See this page about slice tricks
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Paperclip::Errors::MissingRequiredValidatorError with Rails 4
...line to your Post model, after specifying has_attached_file :image
Option 1: Validate content type
validates_attachment_content_type :image, :content_type => ["image/jpg", "image/jpeg", "image/png", "image/gif"]
-OR- another way
validates_attachment :image, content_type: { content_type: ["im...