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One-line list comprehension: if-else variants
...sion you're returning for each element. Thus you need:
[ x if x%2 else x*100 for x in range(1, 10) ]
The confusion arises from the fact you're using a filter in the first example, but not in the second. In the second example you're only mapping each value to another, using a ternary-operator expr...
How do I install an old version of Django on virtualenv?
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There was never a Django 1.0.7. The 1.0 series only went up to 1.0.4. You can see all the releases in the tags section of the Django code repository.
However to answer your question, don't use easy_install, use pip. (If it's not already installed, do ...
Choosing the default value of an Enum type without having to change values
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The default for an enum (in fact, any value type) is 0 -- even if that is not a valid value for that enum. It cannot be changed.
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Calculate total seconds in PHP DateInterval
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209
Could you not compare the time stamps instead?
$now = new DateTime('now');
$diff = $date->...
How do I test if a variable is a number in Bash?
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One approach is to use a regular expression, like so:
re='^[0-9]+$'
if ! [[ $yournumber =~ $re ]] ; then
echo "error: Not a number" >&2; exit 1
fi
If the value is not necessarily an integer, consider amending the regex appropriately; for instance:
^[0-9]+([.][0-9]+)?$
....
PDO Prepared Inserts multiple rows in single query
...atement to look like.
Now, the code:
function placeholders($text, $count=0, $separator=","){
$result = array();
if($count > 0){
for($x=0; $x<$count; $x++){
$result[] = $text;
}
}
return implode($separator, $result);
}
$pdo->beginTransaction();...
Using C# reflection to call a constructor
...ic Addition(int a)
{
Console.WriteLine("Constructor called, a={0}", a);
}
}
class Test
{
static void Main()
{
Type type = typeof(Addition);
ConstructorInfo ctor = type.GetConstructor(new[] { typeof(int) });
object instance = ctor.Invoke(new object[] {...
Drop all duplicate rows across multiple columns in Python Pandas
...ort pandas as pd
df = pd.DataFrame({"A":["foo", "foo", "foo", "bar"], "B":[0,1,1,1], "C":["A","A","B","A"]})
df.drop_duplicates(subset=['A', 'C'], keep=False)
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Switch statement for greater-than/less-than
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Custom ImageView with drop shadow
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answered Dec 10 '10 at 2:43
Kevin CoppockKevin Coppock
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