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Include all existing fields and add new fields to document
...s the new fields.
db.collection.aggregate([
{ "$addFields": { "custom_field": "$obj.obj_field1" } }
])
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TypeError: Missing 1 required positional argument: 'self'
...p.getPumps()
Small example -
>>> class TestClass:
def __init__(self):
print("in init")
def testFunc(self):
print("in Test Func")
>>> testInstance = TestClass()
in init
>>> testInstance.testFunc()
in Test Func
...
Is it expensive to use try-catch blocks even if an exception is never thrown?
...
public class TryFinally {
public TryFinally();
Code:
0: aload_0
1: invokespecial #1 // Method java/lang/Object."<init>":()V
4: return
public static void main(java.lang.String[]) throws java.lang.Throwable;
Code:
0: new #2 ...
Elegant way to invert a map in Scala
...
Assuming values are unique, this works:
(Map() ++ origMap.map(_.swap))
On Scala 2.8, however, it's easier:
origMap.map(_.swap)
Being able to do that is part of the reason why Scala 2.8 has a new collection library.
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Getting the last argument passed to a shell script
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The simplest answer for bash 3.0 or greater is
_last=${!#} # *indirect reference* to the $# variable
# or
_last=$BASH_ARGV # official built-in (but takes more typing :)
That's it.
$ cat lastarg
#!/bin/bash
# echo the last arg given:
_last=${!#}
echo $_last
_last...
Remove blank attributes from an Object in Javascript
...a simple solution:
var obj = {name: 'John', age: null};
var compacted = _.pickBy(obj);
This will only work with lodash 4, pre lodash 4 or underscore.js, use _.pick(obj, _.identity);
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Sending HTTP POST Request In Java
...alue(), "UTF-8"));
byte[] out = sj.toString().getBytes(StandardCharsets.UTF_8);
int length = out.length;
We can then attach our form contents to the http request with proper headers and send it.
http.setFixedLengthStreamingMode(length);
http.setRequestProperty("Content-Type", "application/x-www-f...
将Linux代码移植到Windows的简单方法 - 操作系统(内核) - 清泛网 - 专注C/C++及内核技术
...（Header File）的包含问题。在Config.h中定义了很多类似HAVE_XXXX_H。比如定义HAVE_CONFIG_H为1表示工程中可以使用config.h。
#define HAVE_MALLOC_H 1表示可以在工程中使用Malloc.h头文件。通过调整这些定义值，可以去除一些Windows平台下面没有...
How to set a value of a variable inside a template code?
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If you need to declare a list, use make_list. docs.djangoproject.com/en/1.9/ref/templates/builtins/#make-list
– MrValdez
Jul 1 '16 at 7:55
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Iterating Over Dictionary Key Values Corresponding to List in Python
...ict (league) itself, or league.keys():
for team in league.keys():
runs_scored, runs_allowed = map(float, league[team])
You can also iterate over both the keys and the values at once by iterating over league.items():
for team, runs in league.items():
runs_scored, runs_allowed = map(float,...