枕梦

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枕梦 2025-01-31 23:13:58

您的& operator 不是您通缉。 Python中的& 是A bitwise ,而不是逻辑和,它是 and

将代码更改为类似信息

conditions = [
    (np.where(df['DD'].eq('No DD Required'))),
    (np.where(df['DD'].eq('DD Required'))) and (np.where(df['On Direct Debit'].eq('No'))),
    (np.where(df['DD'].eq('DD Required'))) and (np.where(df['On Direct Debit'].eq('Yes')))
    ]

,以获取更多信息,a

Your & operator is not the one you wanted. & in python is a bitwise AND, not the logical AND, which is and.

Change your code to something like

conditions = [
    (np.where(df['DD'].eq('No DD Required'))),
    (np.where(df['DD'].eq('DD Required'))) and (np.where(df['On Direct Debit'].eq('No'))),
    (np.where(df['DD'].eq('DD Required'))) and (np.where(df['On Direct Debit'].eq('Yes')))
    ]

for more info, a discussion of the distinction between these different ANDs

TypeError:&:' tuple'和元组'

枕梦 2025-01-31 15:54:24

看来我的ECS任务之一使用了任务定义的较旧版本,并且没有正确的权限设置。更新后,它似乎可以正常工作。

It appears that one of my ECS tasks used an older version of the Task definition and it didn't have the correct permissions set. After I updated it, it seems to work fine no.

AWS SES身份验证的春季启动问题

枕梦 2025-01-31 04:28:19

发现我的手臂默认前缀是错误的: - /usr/local MacOS Intel上的 - /opt/opt/homebrew macos臂上的 - /home/home/home/linuxbrew 在Linux上------为了修复它,我不得不卸载Homebrew,在此处找到: github.com/homebrew/install#uninstall-homebrew 然后我不得不重新安装它,在同一链接处找到。重新安装它,将默认前缀从错误的/opt/homebrew 更改为正确的/usr/local/local 前缀

Found out that my ARM default prefix is wrong: - /usr/local on macOS intel - /opt/homebrew on macOS ARM - /home/linuxbrew on Linux ------ In order to fix it I had to uninstall Homebrew, found here: github.com/homebrew/install#uninstall-homebrew And then I had to then reinstall it, found at same link. Reinstalling it changed the default prefix from the incorrect /opt/homebrew to the correct /usr/local prefix

不良CPU类型中可执行的Mac Intel Core

枕梦 2025-01-30 16:16:50

但是,您可以创建自己的功能界面,如下所示:


interface IntVarArgsConsumer {
        void accept(int ...s);
}
    
IntVarArgsConsumer printArray = arr-> System.out.println(Arrays.toString(arr));
        
printArray.accept(1,2,3,4,5);
printArray.accept(1,2,3);

打印

[1, 2, 3, 4, 5]
[1, 2, 3]

,但我警告您不是混合通用类型参数 varargs 。否则,您可以污染堆并获得 ClassCastExceptions 。如果您只想处理 strings ,请使用字符串类型。如果对象,请使用对象类型。但是没有某种类型 r 您可能会在其他方法中看到。

But you can create your own functional interface as follows:


interface IntVarArgsConsumer {
        void accept(int ...s);
}
    
IntVarArgsConsumer printArray = arr-> System.out.println(Arrays.toString(arr));
        
printArray.accept(1,2,3,4,5);
printArray.accept(1,2,3);

prints

[1, 2, 3, 4, 5]
[1, 2, 3]

But I caution you not to mix generic type parameters and varargs. Otherwise you can pollute the heap and get ClassCastExceptions. If you just want to process Strings, then use the String type. If Objects, use the Object type. But not some type R as you might see in other methods.

带有varargs的消费者

枕梦 2025-01-30 08:28:39

它是因为当您显示flex时,即使显示了flex,即使它们显示为块,flex都会使它们在线显示,因此它将占用最小空间,而不是父母的100%宽度,因此您需要给每个孩子更多的宽度才能看到文本位于DIV的中心

,或者如果您想连续显示所有文本,但中心只需添加正当内容:中心和对位项目:中心,这些是给父母的

it because when u display flex all the childs even though they are displayed block, flex will make them be displayed inline so it will take the minimum space instead of 100% width of the parent, so you need to give each child more width to see that the text is in the center of it's div

or if you want to display all the text in a row but center just add justify-content: center and align-items: center, these are for the parent

文本偏好:中心属性不工作如何可以ı修复它

枕梦 2025-01-30 07:35:54

确保Java文件的名称匹配ActivityMainBinding的名称
像照片

寄居

“

mainActivity

Make sure that the name of the java file matches the name of ActivityMainBinding
like the photo

HomeActivity

1

MainActivity

2

可以在底部导航视图中解决绑定

枕梦 2025-01-30 07:15:17

用带有圆形盒装的容器包裹底部导航栏。使用夹克删除背景。设置子底部纳维式栏,并使用底部划分为操作和路由。

    import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: Test_BottomNavBar(),
    );
  }
}

class Test_BottomNavBar extends StatefulWidget {
  Test_BottomNavBar({Key? key}) : super(key: key);

  @override
  State<Test_BottomNavBar> createState() => _Test_BottomNavBarState();
}

class _Test_BottomNavBarState extends State<Test_BottomNavBar> {
  int _current_index=0;
  @override
  Widget build(BuildContext context) {
    return 
    Scaffold(appBar: AppBar(title:Text("Bottom Nav Bar")),body:
    
    Container(
      height: double.infinity,
      width:double.infinity,
      decoration: BoxDecoration(
        image: DecorationImage(
          image:AssetImage("assets/images/background.png"),
          fit:BoxFit.cover),
        
      ),
      child:
      Center(
      child:Text("Bottom Nav Bar",style:TextStyle(fontSize: 60,color:Colors.white))
      
      ),
    ),
     

    bottomNavigationBar:
    Container(                                             
  decoration: BoxDecoration(                                                   
    borderRadius: BorderRadius.only(                                           
      topRight: Radius.circular(20), topLeft: Radius.circular(20)),            
    boxShadow: [                                                               
      BoxShadow(color: Colors.green, spreadRadius: 0, blurRadius: 10),       
    ],                                                                         
  ),                                                                           
  child: ClipRRect(                                                            
    borderRadius: BorderRadius.only(                                           
    topLeft: Radius.circular(20.0),                                            
    topRight: Radius.circular(20.0),                                           
    ),         
    
     child:BottomNavigationBar(
      currentIndex: _current_index,
      selectedItemColor: Colors.orange,
        
      onTap:(int index){
          setState(() {
            _current_index=index;
          });

      },
      items:[
        BottomNavigationBarItem(
          icon: Icon(Icons.home)
          ,label:"Home"
        ),
        BottomNavigationBarItem(
          icon: Icon(Icons.email),
          label:"Email"
        )
      ]

    ),
    )))
    ;
  }
}

Wrap the Bottom Navigation bar with a Container with a rounded BoxDecoration. Use the cliprect to remove the background. Setup the child BottomNavigationBar with the BottomNavigationBarItems for the actions and routing.

    import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: Test_BottomNavBar(),
    );
  }
}

class Test_BottomNavBar extends StatefulWidget {
  Test_BottomNavBar({Key? key}) : super(key: key);

  @override
  State<Test_BottomNavBar> createState() => _Test_BottomNavBarState();
}

class _Test_BottomNavBarState extends State<Test_BottomNavBar> {
  int _current_index=0;
  @override
  Widget build(BuildContext context) {
    return 
    Scaffold(appBar: AppBar(title:Text("Bottom Nav Bar")),body:
    
    Container(
      height: double.infinity,
      width:double.infinity,
      decoration: BoxDecoration(
        image: DecorationImage(
          image:AssetImage("assets/images/background.png"),
          fit:BoxFit.cover),
        
      ),
      child:
      Center(
      child:Text("Bottom Nav Bar",style:TextStyle(fontSize: 60,color:Colors.white))
      
      ),
    ),
     

    bottomNavigationBar:
    Container(                                             
  decoration: BoxDecoration(                                                   
    borderRadius: BorderRadius.only(                                           
      topRight: Radius.circular(20), topLeft: Radius.circular(20)),            
    boxShadow: [                                                               
      BoxShadow(color: Colors.green, spreadRadius: 0, blurRadius: 10),       
    ],                                                                         
  ),                                                                           
  child: ClipRRect(                                                            
    borderRadius: BorderRadius.only(                                           
    topLeft: Radius.circular(20.0),                                            
    topRight: Radius.circular(20.0),                                           
    ),         
    
     child:BottomNavigationBar(
      currentIndex: _current_index,
      selectedItemColor: Colors.orange,
        
      onTap:(int index){
          setState(() {
            _current_index=index;
          });

      },
      items:[
        BottomNavigationBarItem(
          icon: Icon(Icons.home)
          ,label:"Home"
        ),
        BottomNavigationBarItem(
          icon: Icon(Icons.email),
          label:"Email"
        )
      ]

    ),
    )))
    ;
  }
}

如何将背景颜色删除底部导航栏(颤音)中的容器?

枕梦 2025-01-30 03:22:01

由于您的功能没有返回,因此返回未定义。
您可以尝试readfilesync

示例:

 const render = () => file.readFileSync("file.txt" , { encoding: "utf-8" });
 console.log(render())

 const render = () => {
   return new Promise((resolve, reject) => {
     file.readFile(`file.txt`, { encoding: "utf-8" }, (err, data) => {
        if (err) reject(err);
        resolve(data);
     });
   });  
 }; 

 render().then(console.log)

Since there is no return in your function, it returns undefined.
You can try readFileSync

Example:

 const render = () => file.readFileSync("file.txt" , { encoding: "utf-8" });
 console.log(render())

or

 const render = () => {
   return new Promise((resolve, reject) => {
     file.readFile(`file.txt`, { encoding: "utf-8" }, (err, data) => {
        if (err) reject(err);
        resolve(data);
     });
   });  
 }; 

 render().then(console.log)

带有自定义功能的文件数据

枕梦 2025-01-29 17:46:33

使用方法:

In [5]: df.query("country in @countries_to_keep")
Out[5]:
  countries
1        UK
3     China

In [6]: df.query("country not in @countries_to_keep")
Out[6]:
  countries
0        US
2   Germany

Alternative solution that uses .query() method:

In [5]: df.query("country in @countries_to_keep")
Out[5]:
  countries
1        UK
3     China

In [6]: df.query("country not in @countries_to_keep")
Out[6]:
  countries
0        US
2   Germany

如何使用&#x27; in&#x27;和&#x27;不在&#x27;像在SQL中

枕梦 2025-01-29 17:24:29

无论您使用哪种语言,参考始终是代表时的值。

获取框外视图的外部,让我们看一下汇编或一些低级别的内存管理。在CPU级别上,如果将其写入内存或CPU寄存器之一,请立即将任何内容引用到任何事物。 (这就是为什么 pointer 是一个很好的定义。它是一个值,同时具有目的)。

内存中的数据具有位置,在该位置有一个值(字节,单词,无论如何)。在组装中,我们有一个方便的解决方案,可以将名称 位置(又称变量),但是当编译代码时,汇编器简单地替换 name 在指定的位置就像您的浏览器一样,用IP地址代替域名。

直到核心,在技术上不可能在不代表任何语言的情况下对任何语言的任何内容进行引用(当它立即成为值时)。

假设我们有一个可变的foo,其位置位于内存中的第47个字节,其 value 是5。我们有另一个变量 ref2foo 位于内存中的第223个字节,其值将为47。此Ref2Foo可能是技术变量,而不是由程序明确创建。如果您只看5和47没有任何其他信息,您将仅看到两个
如果您将它们用作参考,则可以到达 5 我们必须旅行:

(Name)[Location] -> [Value at the Location]
---------------------
(Ref2Foo)[223]  -> 47
(Foo)[47]       -> 5

这是跳伞表的工作方式。

如果我们想用Foo的值调用方法/函数/过程,则有几种可能的方法将变量传递给该方法,具体取决于 Language 及其几种方法调用模式:

  1. 5被复制到CPU寄存器之一(即eax)。
  2. 5被推到堆栈。
  3. 47被复制到CPU寄存器之一
  4. 47推到堆栈中。
  5. 223被复制到CPU登记册之一。
  6. 223被推到堆栈。

在上述值以上的每个情况下,已经创建了现有值的 ,现在它正在使用接收方法来处理它。当您在方法中写“ foo”时,它要么从eax中读取,要么自动 或double删除,该过程取决于语言的工作原理和/或foo指示的类型。这是对开发人员隐藏的,直到她绕过退出过程。因此,当表示时,A 参考是A value ,因为参考是必须处理的值(在语言层面上)。

现在,我们已经将foo传递给了该方法:

  • 在情况1和2中。如果更改foo( foo = 9 ),它只会影响本地范围,因为您拥有该值的副本。从该方法内部,我们甚至无法确定原始FOO所在的内存中的位置。
  • 在情况3和4中。如果您使用默认语言构造并更改foo( foo = 11 ),它可能会在全球上更改foo(取决于语言,即Java或pascal的 procepture Findmin(X,Y,Z:Integer; var m :integer); )。但是,如果该语言允许您规避解除过程,则可以更改 47 ,对 49 说。那时,如果您阅读了Foo,Foo似乎已经更改了,因为您已将本地指针更改为。而且,如果要在方法内修改此foo( foo = 12 ),则可能会fubar fubar执行程序(aka。segfault),因为您会写入与预期的不同内存中甚至修改一个注定要保存可执行程序的区域并写入它将修改运行代码(FOO现在不在 47 )。但是foo的 47 的值没有在全球变化,只有该方法中的一个,因为 47 也是该方法的副本。
  • 在案例5和6中。如果您修改 223 在该方法中,它会创建与3或4中相同的混乱。指针)但这仍然是一个本地问题,因为223被复制。但是,如果您能够解释 ref2foo (即 223 ),请访问并修改指向值 47 ,例如 49 ,它将影响foo 全球,因为在这种情况下,方法获得了 223 的副本,但是引用 47 存在一次,然后将其更改为 49 将带领每个 ref2foo 双重降级到错误的值。

挑剔微不足道的细节,即使是逐个引用的语言也会将值传递给函数,但是这些功能知道他们必须将其用于解释目的。这种通过的参考文献是从程序员中隐藏的,因为它实际上是没有用的,术语仅是通过逐次参考

严格的通过也是没有用的,这意味着每当我们将以数组称为参数的方法时,必须复制100 mbyte数组-价值。每种语言都会传递对这个巨大数组(作为值)的引用,并且如果可以在方法内部的本地更改该数组,或者允许该方法(如Java所做的那样)在全球修改数组(从呼叫者的视图)和几种语言允许修改参考本身的值。

因此,简而>值是参考的表示。

A reference is always a value when represented, no matter what language you use.

Getting an outside of the box view, let's look at Assembly or some low level memory management. At the CPU level a reference to anything immediately becomes a value if it gets written to memory or to one of the CPU registers. (That is why pointer is a good definition. It is a value, which has a purpose at the same time).

Data in memory has a Location and at that location there is a value (byte,word, whatever). In Assembly we have a convenient solution to give a Name to certain Location (aka variable), but when compiling the code, the assembler simply replaces Name with the designated location just like your browser replaces domain names with IP addresses.

Down to the core it is technically impossible to pass a reference to anything in any language without representing it (when it immediately becomes a value).

Lets say we have a variable Foo, its Location is at the 47th byte in memory and its Value is 5. We have another variable Ref2Foo which is at 223rd byte in memory, and its value will be 47. This Ref2Foo might be a technical variable, not explicitly created by the program. If you just look at 5 and 47 without any other information, you will see just two Values.
If you use them as references then to reach to 5 we have to travel:

(Name)[Location] -> [Value at the Location]
---------------------
(Ref2Foo)[223]  -> 47
(Foo)[47]       -> 5

This is how jump-tables work.

If we want to call a method/function/procedure with Foo's value, there are a few possible way to pass the variable to the method, depending on the language and its several method invocation modes:

  1. 5 gets copied to one of the CPU registers (ie. EAX).
  2. 5 gets PUSHd to the stack.
  3. 47 gets copied to one of the CPU registers
  4. 47 PUSHd to the stack.
  5. 223 gets copied to one of the CPU registers.
  6. 223 gets PUSHd to the stack.

In every cases above a value - a copy of an existing value - has been created, it is now upto the receiving method to handle it. When you write "Foo" inside the method, it is either read out from EAX, or automatically dereferenced, or double dereferenced, the process depends on how the language works and/or what the type of Foo dictates. This is hidden from the developer until she circumvents the dereferencing process. So a reference is a value when represented, because a reference is a value that has to be processed (at language level).

Now we have passed Foo to the method:

  • in case 1. and 2. if you change Foo (Foo = 9) it only affects local scope as you have a copy of the Value. From inside the method we cannot even determine where in memory the original Foo was located.
  • in case 3. and 4. if you use default language constructs and change Foo (Foo = 11), it could change Foo globally (depends on the language, ie. Java or like Pascal's procedure findMin(x, y, z: integer;var m: integer);). However if the language allows you to circumvent the dereference process, you can change 47, say to 49. At that point Foo seems to have been changed if you read it, because you have changed the local pointer to it. And if you were to modify this Foo inside the method (Foo = 12) you will probably FUBAR the execution of the program (aka. segfault) because you will write to a different memory than expected, you can even modify an area that is destined to hold executable program and writing to it will modify running code (Foo is now not at 47). BUT Foo's value of 47 did not change globally, only the one inside the method, because 47 was also a copy to the method.
  • in case 5. and 6. if you modify 223 inside the method it creates the same mayhem as in 3. or 4. (a pointer, pointing to a now bad value, that is again used as a pointer) but this is still a local problem, as 223 was copied. However if you are able to dereference Ref2Foo (that is 223), reach to and modify the pointed value 47, say, to 49, it will affect Foo globally, because in this case the methods got a copy of 223 but the referenced 47 exists only once, and changing that to 49 will lead every Ref2Foo double-dereferencing to a wrong value.

Nitpicking on insignificant details, even languages that do pass-by-reference will pass values to functions, but those functions know that they have to use it for dereferencing purposes. This pass-the-reference-as-value is just hidden from the programmer because it is practically useless and the terminology is only pass-by-reference.

Strict pass-by-value is also useless, it would mean that a 100 Mbyte array should have to be copied every time we call a method with the array as argument, therefore Java cannot be stricly pass-by-value. Every language would pass a reference to this huge array (as a value) and either employs copy-on-write mechanism if that array can be changed locally inside the method or allows the method (as Java does) to modify the array globally (from the caller's view) and a few languages allows to modify the Value of the reference itself.

So in short and in Java's own terminology, Java is pass-by-value where value can be: either a real value or a value that is a representation of a reference.

是java“通过参考”或“逐个价值”?

枕梦 2025-01-29 08:28:01

您当前的方法是试图将指导孩子定位为“&gt;”。

我不确定这些课程是否用于网站上的其他任何内容,但如果没有,我会跳过直接的儿童选择器。我也不确定为什么您将“空” divs作为“包装器”?如果背后没有具体的想法,我会做以下内容。

.sectionWrapper .textClass {
  margin-top: -3rem;
}

.sectionWrapper:first-child .textClass {
  margin-top: -1rem;
}
<div class="parent">
  <section class="sectionWrapper">
    <div class="textClass">
      <span>My text</span>
    </div>
  </section>

  <section class="sectionWrapper">
    <div class="textClass">
      <span>My text</span>
    </div>
  </section>

  <section class="sectionWrapper">
    <div class="textClass">
      <span>My text</span>
    </div>
  </section>
</div>

如果您真的想“优化”您的HTML/CSS,我将使用更多直接和特定的类而不是“嵌套”选择器。

.section-wrapper__text {
  margin-top: -3rem;
}

.section_wrapper:first-child > .section-wrapper__text {
  margin-top: -1rem;
}
<div class="parent">
  <section class="section-wrapper">
    <div class="section-wrapper__text">
      <span>My text</span>
    </div>
  </section>

  <section class="section-wrapper">
    <div class="section-wrapper__text">
      <span>My text</span>
    </div>
  </section>
</div>

Your current approach is trying to target direct children to parent with the ">".

I'm not sure if the classes are used for anything else on the site but if not I would skip the direct child selector. I'm also not sure why you have "empty" divs as "wrappers"? If there is no specific thought behind it I would do the following.

.sectionWrapper .textClass {
  margin-top: -3rem;
}

.sectionWrapper:first-child .textClass {
  margin-top: -1rem;
}
<div class="parent">
  <section class="sectionWrapper">
    <div class="textClass">
      <span>My text</span>
    </div>
  </section>

  <section class="sectionWrapper">
    <div class="textClass">
      <span>My text</span>
    </div>
  </section>

  <section class="sectionWrapper">
    <div class="textClass">
      <span>My text</span>
    </div>
  </section>
</div>

If you really want to "optimise" your html/css I would use more direct and specific class instead of "nesting" selectors.

.section-wrapper__text {
  margin-top: -3rem;
}

.section_wrapper:first-child > .section-wrapper__text {
  margin-top: -1rem;
}
<div class="parent">
  <section class="section-wrapper">
    <div class="section-wrapper__text">
      <span>My text</span>
    </div>
  </section>

  <section class="section-wrapper">
    <div class="section-wrapper__text">
      <span>My text</span>
    </div>
  </section>
</div>

如何将不同的CSS应用于CSS的不同儿童元素?

枕梦 2025-01-29 08:19:03

我遇到了同样的问题,我执行了其他线程中提到的PowerShell脚本(作为管理员运行PowerShell),重新启动了我的PC并使用了重新下载的安装程序(来自错误消息中的URL)。这次安装程序通过了。希望它有帮助!

I had the same issue, I executed the Powershell script as mentioned in the other thread (run powershell as an administrator), restarted my PC and used the re-downloaded installer (from the url in the error message). This time the installer went through. Hope it helps!

Microsoft SQL Server Express:此版本的安装程序不再支持

枕梦 2025-01-29 06:30:37

重复的数据

# aggregate data
df2 = df.groupby('Year')[['Current Amount', 'Previous Amount']].sum()
# ensure having all intermediate years
df2 = df2.reindex(range(df2.index.min(), df2.index.max()+1))

# compute the change and merge
df.merge(df2['Current Amount'].sub(df2['Previous Amount'].shift()).rename('Change'),
         on='Year', how='left')

输出:

   Year  Current Amount  Previous Amount   Type   Change
0  2021           22000            36000  C5 70      NaN
1  2022           26000            48000  C4 68 -10000.0
2  2023           76440            34000  C5 70  28440.0
3  2024           21399            12000  C4 68  35899.0
4  2024           22000            11000  C4 34  35899.0
5  2024           26500            13000  C4 23  35899.0
6  2025           16000            34000  C4 68  90000.0
7  2025           76000            22000  C4 34  90000.0
8  2025           34000            64000  C4 23  90000.0

较旧的答案

IIUC,假设连续几年使用:

df['Change'] = df['Current Amount'].sub(df['Previous Amount'].shift())

另外:确保映射上一年,使用:

s = df.set_index('Year')['Previous Amount']
s.index += 1

df['Change'] = df['Current Amount'].sub(df['Year'].map(s))

输出:

   Year  Current Amount  Previous Amount   Type   Change
0  2021           22000            36000  C5 70      NaN
1  2022           26000            48000  C4 68 -10000.0
2  2023           76440            34000  C5 70  28440.0
3  2024           21399            12000  C4 68 -12601.0

duplicated data

# aggregate data
df2 = df.groupby('Year')[['Current Amount', 'Previous Amount']].sum()
# ensure having all intermediate years
df2 = df2.reindex(range(df2.index.min(), df2.index.max()+1))

# compute the change and merge
df.merge(df2['Current Amount'].sub(df2['Previous Amount'].shift()).rename('Change'),
         on='Year', how='left')

output:

   Year  Current Amount  Previous Amount   Type   Change
0  2021           22000            36000  C5 70      NaN
1  2022           26000            48000  C4 68 -10000.0
2  2023           76440            34000  C5 70  28440.0
3  2024           21399            12000  C4 68  35899.0
4  2024           22000            11000  C4 34  35899.0
5  2024           26500            13000  C4 23  35899.0
6  2025           16000            34000  C4 68  90000.0
7  2025           76000            22000  C4 34  90000.0
8  2025           34000            64000  C4 23  90000.0

older answer

IIUC, assuming consecutive years, use:

df['Change'] = df['Current Amount'].sub(df['Previous Amount'].shift())

Alternatively, to ensure mapping the previous year, use:

s = df.set_index('Year')['Previous Amount']
s.index += 1

df['Change'] = df['Current Amount'].sub(df['Year'].map(s))

output:

   Year  Current Amount  Previous Amount   Type   Change
0  2021           22000            36000  C5 70      NaN
1  2022           26000            48000  C4 68 -10000.0
2  2023           76440            34000  C5 70  28440.0
3  2024           21399            12000  C4 68 -12601.0

我如何从另一年期之前的另一列行中减去一个列行的值?

枕梦 2025-01-29 06:11:42

您可以直接使用集合类的计数()。

if($companies->count() > 0)

使用以下代码,当时关系是一对一的

if($companies)

you can directly use count() of the collection class.

if($companies->count() > 0)

Use below code, when the relation is one-to-one

if($companies)

检查数组是否为空时,未定义的数组键0错误

枕梦 2025-01-28 21:09:02

尽管承诺和回调在许多情况下都可以正常工作,但后方表达出类似的内容是一种痛苦:

if (!name) {
  name = async1();
}
async2(name);

您最终会通过 async1 ;检查 name 是否未定义,并相应地致电回调。

async1(name, callback) {
  if (name)
    callback(name)
  else {
    doSomething(callback)
  }
}

async1(name, async2)

虽然好的在小例子中,当您有很多类似的情况和涉及错误处理时,它会很烦人。

纤维有助于解决问题。

var Fiber = require('fibers')

function async1(container) {
  var current = Fiber.current
  var result
  doSomething(function(name) {
    result = name
    fiber.run()
  })
  Fiber.yield()
  return result
}

Fiber(function() {
  var name
  if (!name) {
    name = async1()
  }
  async2(name)
  // Make any number of async calls from here
}

您可以检查项目此处

While promises and callbacks work fine in many situations, it is a pain in the rear to express something like:

if (!name) {
  name = async1();
}
async2(name);

You'd end up going through async1; check if name is undefined or not and call the callback accordingly.

async1(name, callback) {
  if (name)
    callback(name)
  else {
    doSomething(callback)
  }
}

async1(name, async2)

While it is okay in small examples it gets annoying when you have a lot of similar cases and error handling involved.

Fibers helps in solving the issue.

var Fiber = require('fibers')

function async1(container) {
  var current = Fiber.current
  var result
  doSomething(function(name) {
    result = name
    fiber.run()
  })
  Fiber.yield()
  return result
}

Fiber(function() {
  var name
  if (!name) {
    name = async1()
  }
  async2(name)
  // Make any number of async calls from here
}

You can checkout the project here.

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