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hadoop No FileSystem for scheme: file
...is a typical case of the maven-assembly plugin breaking things.
Why this happened to us
Different JARs (hadoop-commons for LocalFileSystem, hadoop-hdfs for DistributedFileSystem) each contain a different file called org.apache.hadoop.fs.FileSystem in their META-INFO/services directory. This file l...
What is the most efficient way of finding all the factors of a number in Python?
...om functools import reduce
def factors(n):
return set(reduce(list.__add__,
([i, n//i] for i in range(1, int(n**0.5) + 1) if n % i == 0)))
This will return all of the factors, very quickly, of a number n.
Why square root as the upper limit?
sqrt(x) * sqrt(x) = x. So if t...
How to watch for array changes?
...ods or the length property).
function ObservableArray(items) {
var _self = this,
_array = [],
_handlers = {
itemadded: [],
itemremoved: [],
itemset: []
};
function defineIndexProperty(index) {
if (!(index in _self)) {
Object.defineProperty...
I'm getting Key error in python
...ts?
From the official python docs:
exception KeyError
Raised when a mapping (dictionary) key is not found in the set of
existing keys.
For example:
>>> mydict = {'a':'1','b':'2'}
>>> mydict['a']
'1'
>>> mydict['c']
Traceback (most recent call last):
File "<...
What does the “yield” keyword do?
...ou create the method of the node object that will return the generator
def _get_child_candidates(self, distance, min_dist, max_dist):
# Here is the code that will be called each time you use the generator object:
# If there is still a child of the node object on its left
# AND if the d...
Can a dictionary be passed to django models on create?
...our model is called MyModel:
# create instance of model
m = MyModel(**data_dict)
# don't forget to save to database!
m.save()
As for your second question, the dictionary has to be the final argument. Again, extra and extra2 should be fields in the model.
m2 =MyModel(extra='hello', extra2='world'...
What is the difference between match_parent and fill_parent?
...
if I write app for both 1.6 and 2.2, I will use fill_parent for compatibility, is it right?
– emeraldhieu
Aug 2 '11 at 14:09
...
Get exception description and stack trace which caused an exception, all as a string
...
See the traceback module, specifically the format_exc() function. Here.
import traceback
try:
raise ValueError
except ValueError:
tb = traceback.format_exc()
else:
tb = "No error"
finally:
print tb
...
NSLog the method name with Objective-C in iPhone
...
print(__FUNCTION__) // Swift
NSLog(@"%@", NSStringFromSelector(_cmd)); // Objective-C
Swift 3 and above
print(#function)
share
|
...
What's the 'environment' task in Rake?
... the rake tasks are, and I found an empty task definition that depends on 'app:environment', but I can't find the definition of the app:environment task. github.com/rails/rails/blob/master/railties/lib/rails/tasks/…
– odigity
Jan 27 '15 at 20:18
...