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How to extract the file name from URI returned from Intent.ACTION_GET_CONTENT?
...Activity):
public String getFileName(Uri uri) {
String result = null;
if (uri.getScheme().equals("content")) {
Cursor cursor = getContentResolver().query(uri, null, null, null, null);
try {
if (cursor != null && cursor.moveToFirst()) {
result = cursor.getString(cur...
Which cryptographic hash function should I choose?
The .NET framework ships with 6 different hashing algorithms:
9 Answers
9
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When to use Preorder, Postorder, and Inorder Binary Search Tree Traversal strategies
I realized recently that while having used BST's plenty in my life, I've never even contemplated using anything but Inorder traversal (while I am aware of and know how easy it is to adapt a program to use pre/post-order traversal).
...
How to check if a python module exists without importing it
I need to know if a python module exists, without importing it.
13 Answers
13
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How do I find out if first character of a string is a number?
In Java is there a way to find out if first character of a string is a number?
5 Answers
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How can I pass a list as a command-line argument with argparse?
...t with argparse. Ever.
Let's take a look in more detail at some of the different ways one might try to do this, and the end result.
import argparse
parser = argparse.ArgumentParser()
# By default it will fail with multiple arguments.
parser.add_argument('--default')
# Telling the type to be a...
Android Fragment handle back button press [duplicate]
...ace( R.id.fragment, new MyFragment() ).addToBackStack( "tag" ).commit();
If you require more detailed control (i.e. when some Fragments are visible, you want to suppress the back key) you can set an OnKeyListener on the parent view of your fragment:
//You need to add the following line for this s...
Requests — how to tell if you're getting a 404
...
Look at the r.status_code attribute:
if r.status_code == 404:
# A 404 was issued.
Demo:
>>> import requests
>>> r = requests.get('http://httpbin.org/status/404')
>>> r.status_code
404
If you want requests to raise an exception...
How to find Unused Amazon EC2 Security groups
...can't easily (might not even be possible) to delete active security groups if you miss one associated w/another service.
Using the newer AWS CLI tool, I found an easy way to get what I need:
First, get a list of all security groups
aws ec2 describe-security-groups --query 'SecurityGroups[*].GroupId'...
php is null or empty?
...
What you're looking for is:
if($variable === NULL) {...}
Note the ===.
When use ==, as you did, PHP treats NULL, false, 0, the empty string, and empty arrays as equal.
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