尝试 npm 安装一个我刚刚拉下的存储库，我得到了与许多其他人相同的错误：
npm ERR! gyp ERR! stack Error: Can't find Python executable "python", you can set the PYTHON env variable.
所以我在我的 wsl2 实例中安装了 python 并重新启动了我的 shell，得到了同样的错误。然后我就跟着跑了
whereis python
输出如下：
python: /usr/bin/python3.8 /usr/bin/python3.8-config /usr/lib/python3.8 /usr/lib/python3.9 /usr/lib/python2.7 /etc/python3.8 /usr/local/lib/python3.8 /usr/include/python3.8 /mnt/c/Python39/python.exe /mnt/c/Python39/python3.dll /mnt/c/Python39/python39.dll /mnt/c/Users/ethan/AppData/Local/Microsoft/WindowsApps/python.exe /mnt/c/Users/ethan/AppData/Local/Microsoft/WindowsApps/python3.exe
所以我跑了
npm config set python /usr/bin/python3.8
现在，当我尝试再次安装时，出现不同的错误
npm ERR! gyp ERR! stack Error: Command failed: /usr/bin/python3.8 -c import sys; print "%s.%s.%s" % sys.version_info[:3];
我不知道从这里去哪里，因为显然没有其他人遇到过这个错误
我目前正在为 Angular 4 应用程序制定货币格式化程序指令。在解析中去掉数字和小数以外的所有内容，并以字符串化的浮点数结束，但我需要它作为浮点数返回，以便我可以用它进行数学运算。
parse(value: string, fractionSize: number = 2): number {
let val = value.replace(/([^0-9.])+/ig, '');
let [ integer, fraction = "" ] = (val || "").split(this.DECIMAL_SEPARATOR);
integer = integer.replace(new RegExp(this.THOUSANDS_SEPARATOR, "g"), "");
fraction = parseInt(fraction, 10) > 0 && fractionSize > 0
? this.DECIMAL_SEPARATOR + (fraction + PADDING).substring(0, fractionSize)
: "";
let result = `${integer}${fraction}`;
// at this point result = "100.55";
result = parseFloat(result); // this refuses to compile saying "Type 'number' is not assignable ? to …我正在 wsl2 中的 .net core 5 中开发 api，并按照所有文档安装实体框架核心工具。
当我跑步时
dotnet tool list -g
它打印
Package Id Version Commands
--------------------------------------
dotnet-ef 5.0.7 dotnet-ef
但当我跑步时
dotnet ef
或其任何子命令，我明白了
Could not execute because the specified command or file was not found.
Possible reasons for this include:
* You misspelled a built-in dotnet command.
* You intended to execute a .NET program, but dotnet-ef does not exist.
* You intended to run a global tool, but a dotnet-prefixed executable with this name could not …我正在尝试列出输入,我无法编译ngFor.
<div *ngFor="let q of questions; let i = index" class="col-3">
<div class="group">
<input [(ngModel)]="q" [class.ng-not-empty]="q.length > 0">
<span class="bar"></span>
<label>Question {{i}}</label>
</div>
</div>
我的定义如下:
questions: string[];
constructor() {
this.questions = ['blah', 'blah', 'blah'];
}
我得到的错误是:
ERROR in : Error: Cannot assign to a reference or variable!
如果我删除了它的索引定义,我已经尝试了以下所有方法:
*ngfor="let q of questions | index as i"
*ngfor="let q of questions; index as i"