1.Python exit的源码原理
2.ç¨delphiå计ç®å¨
3.Python-发送邮件(带链接、附件、源码源代码)
4.throwableåExceptionçåºå«(详ç»ä¸ç¹)
Python exit的源码原理
在Python中,exit()函数的源码作用是退出程序。然而,源码在实际应用中,源码innodb 源码解读有时可能会遇到exit()函数无法正常退出的源码情况。本文将详细介绍exit()函数的源码原理及其在嵌入式Python解释器中的应用。
在正常的源码Python解释器中,exit()函数实际上是源码一个_sitebuiltins.Quitter类的对象。当调用exit()函数时,源码会执行Quitter类的源码__call__方法,该方法通过抛出SystemExit异常来退出解释器。源码然而,源码在嵌入式Python解释器中,源码C++程序通常会捕获所有异常,包括SystemExit,导致exit()函数失效。
为了解决这个问题,仿饿了么app源码可以使用try-except语句捕获SystemExit异常,并在C++中处理。另外,sys.exit()函数也可以用来退出解释器,它同样通过抛出SystemExit异常来实现。此外,os._exit()函数可以强制退出程序,不会触发异常处理,从而确保程序立即退出。在线教育培训系统源码
需要注意的是,except:与except Exception:在捕获异常时有区别。except:会捕获所有异常,包括SystemExit,而except Exception:只会捕获非SystemExit的异常。因此,在使用except:时,可能会意外捕获到SystemExit异常,导致程序无法正常退出。360vr全景通源码
最后,本文还介绍了如何查看程序返回值以及SystemExit异常的原理。在Python中,可以通过搜索源代码中的“SystemExit”字符串来了解其工作原理。在实际应用中,理解exit()函数的原理对于处理程序退出问题具有重要意义。
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unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, Buttons, StdCtrls, ExtCtrls;
type
TForm1 = class(TForm)
Panel1: TPanel;
Panel2: TPanel;
SpeedButton7: TSpeedButton;
SpeedButton8: TSpeedButton;
SpeedButton9: TSpeedButton;
SpeedButton: TSpeedButton;
SpeedButton4: TSpeedButton;
SpeedButton5: TSpeedButton;
SpeedButton6: TSpeedButton;
SpeedButton: TSpeedButton;
SpeedButton1: TSpeedButton;
SpeedButton2: TSpeedButton;
SpeedButton3: TSpeedButton;
SpeedButton: TSpeedButton;
SpeedButton: TSpeedButton;
SpeedButton: TSpeedButton;
SpeedButton: TSpeedButton;
StaticText1: TStaticText;
SpeedButton0: TSpeedButton;
SpeedButton: TSpeedButton;
SpeedButton: TSpeedButton;
GroupBox1: TGroupBox;
procedure SpeedButton1Click(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure SpeedButtonClick(Sender: TObject);
procedure SpeedButtonClick(Sender: TObject);
procedure SpeedButtonClick(Sender: TObject);
procedure SpeedButtonClick(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
restart: Boolean;
isfirst: Boolean;
fir_num,sec_num: String;
sign: integer;
result: real;
save: String;
implementation
{ $R *.dfm}
function count(sign: integer):real;
begin
case sign of
1: result:=strtofloat(fir_num)+strtofloat(sec_num); //为å å·æ¶
2: result:=strtofloat(fir_num)-strtofloat(sec_num); //为åå·æ¶
3: result:=strtofloat(fir_num)*strtofloat(sec_num); //为ä¹å·æ¶
4: begin
try
result:=strtofloat(fir_num)/strtofloat(sec_num); //为é¤å·æ¶
except
ShowMessage('é误!');
form1.close;
end; //é¤æ°ä¸º0æ¶,ååºå¼å¸¸å¤ç
end;
end;
end;
procedure TForm1.SpeedButton1Click(Sender: TObject);
var
i: integer;
begin
if restart then //å¦ææ¯éæ°å¼å§è¾å ¥,åæ¸ é¤åæ¥çæä½æ°,并设置isfirst为True
begin
isfirst:=True;
fir_num:='';
sec_num:='';
restart:=False;
end;
if isfirst then //å¦ææ¯ç¬¬ä¸ä¸ªæä½æ°
begin
if (sender as TSpeedButton).Caption='.' then //å¦æè¾å ¥çæ¯å°æ°ç¹
begin
if (strlen(pChar(fir_num))<=0) then //å¦æ第ä¸ä¸ªæä½æ°å¹¶æªè¾å ¥
fir_num:='0.'
else
for i:= 1 to strlen(pChar(fir_num)) do
if fir_num[i]='.' then exit;
//å¦æ第ä¸ä¸ªä¸å·²å«æå°æ°ç¹èåè¾å ¥å°æ°ç¹,åéåº
end;
if (strlen(pChar(fir_num))>0) and (fir_num[1]='0') then //å¦ææé«ä½ä¸º0
begin
if ((sender as TSpeedButton).Caption='.') then
fir_num:='0.'
else
begin
if strlen(pChar(fir_num))>1 then //å¦ææ¯å°æ°,å继ç»è¾å ¥
fir_num:=fir_num+(sender as TSpeedButton).Caption
else
fir_num:=(sender as TSpeedButton).Caption;
//å¦æä¸æ¯å°æ°,åå»ææé«ä½ç0
end;
end
else
fir_num:=fir_num+(sender as TSpeedButton).Caption;
StaticText1.Caption:=fir_num;
end
else
begin
if (sender as TSpeedButton).Caption='.' then //å¦æ第äºä¸ªæä½æ°å¹¶æªè¾å ¥
begin
if (strlen(pChar(sec_num))<=0) then
sec_num:='0.'
else
for i:= 1 to strlen(pChar(sec_num)) do
if sec_num[i]='.' then exit;
//å¦æ第äºä¸ªä¸å·²å«æå°æ°ç¹èåè¾å ¥å°æ°ç¹,åéåº
end;
if (strlen(pChar(sec_num))>0) and (sec_num[1]='0') then //å¦ææé«ä½ä¸º0
begin
if ((sender as TSpeedButton).Caption='.') then
sec_num:='0.'
else
begin
if strlen(pChar(sec_num))>1 then //å¦ææ¯å°æ°,å继ç»è¾å ¥
sec_num:=sec_num+(sender as TSpeedButton).Caption
else
sec_num:=(sender as TSpeedButton).Caption;
//å¦æä¸æ¯å°æ°,åå»ææé«ä½ç0
end;
end
else
sec_num:=sec_num+(sender as TSpeedButton).Caption;
StaticText1.Caption:=sec_num;
end;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
StaticText1.Caption:='0.'; //设置StaticText1åå§æ¾ç¤ºä¸º0.
restart:=False;
Isfirst:=True;
fir_num:='';
sec_num:='';
end;
procedure TForm1.SpeedButtonClick(Sender: TObject);
begin
if (fir_num<>'') and (sec_num<>'') then
//å¦æ两åæä½æ°é½ä¸ä¸ºç©º
begin
result:=count(sign); //è°ç¨å½æ°,è¿å计ç®ç»æ
fir_num:=floattostr(result);
sec_num:='';
StaticText1.Caption:=floattostr(result);
end;
sign:=(sender as TSpeedButton).Tag;
isfirst:=False;
restart:=False;
end;
procedure TForm1.SpeedButtonClick(Sender: TObject);
begin
if (sec_num<>'') then
//å¦æ第äºä¸ªæä½æ°ä¸ä¸ºç©ºåè¿åç»æ
begin
result:=count(sign);
fir_num:='';
fir_num:=fir_num+floattostr(result);
StaticText1.Caption:=floattostr(result);
sec_num:='';
end;
restart:=true;
end;
procedure TForm1.SpeedButtonClick(Sender: TObject);
begin
restart:=True;
fir_num:='';
sec_num:='';
self.StaticText1.Caption:='0.';
end;
procedure TForm1.SpeedButtonClick(Sender: TObject);
begin
Close;
end;
end.
Python-发送邮件(带链接、附件、源代码)
在众多编程语言中,前端面试中jquery源码Python因其简洁易懂的语法和强大的功能成为许多开发者的选择。Python不仅擅长数据处理、科学计算,还能用于自动化任务,比如发送电子邮件。本文将分享如何使用Python发送带有链接、附件和源代码的邮件。
首先,让我们明确Python发送邮件的思路。尽管可能需要了解一些底层知识,但幸运的是,Python的库已经为我们提供了封装好的接口。这些库简化了邮件发送过程,使得我们只需关注如何使用这些接口,而无需关心复杂的邮件协议。
发送邮件的主要步骤如下:
1. 开启邮箱授权码。这通常需要登录你的邮箱服务提供商(如邮箱)并按照指引操作。完成后,邮箱会发送一个验证码,验证通过后,你将获得授权码。
2. 使用Python库(如smtplib和email)编写脚本来发送邮件。在代码中,你需要替换授权码、收件人邮箱地址、发件人邮箱地址和邮件内容。
3. 验证邮件发送是否成功。可以通过捕获异常或检查邮件是否已成功发送到收件人邮箱来验证。
为了确保代码的实用性,下面提供一个简单的Python脚本示例,用于发送邮件,包含链接、附件和源代码。请根据实际情况调整代码中的邮箱和授权码信息。
python
import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.application import MIMEApplication
# 邮箱配置
smtp_server = 'smtp..com' # 邮箱服务器
smtp_port = # 邮箱服务器端口
email = 'your_email@example.com' # 发件人邮箱地址
password = 'your_password' # 邮箱授权码
# 创建邮件对象
msg = MIMEMultipart()
msg['From'] = email
msg['To'] = 'recipient@example.com' # 收件人邮箱地址
msg['Subject'] = '邮件主题'
# 邮件正文内容
body = '邮件正文内容'
msg.attach(MIMEText(body, 'plain'))
# 添加附件
attachment = 'path/to/your/file' # 附件路径
with open(attachment, 'rb') as f:
part = MIMEApplication(f.read(), Name=attachment.split('/')[-1])
part['Content-Disposition'] = f'attachment; filename="{ part.get_filename()}"'
msg.attach(part)
# 添加源代码链接
link = '/source-code' # 源代码链接
msg.attach(MIMEText(f'查看源代码: { link}', 'html'))
# 发送邮件
try:
server = smtplib.SMTP(smtp_server, smtp_port)
server.starttls()
server.login(email, password)
server.sendmail(email, 'recipient@example.com', msg.as_string())
server.quit()
print('邮件发送成功')
except Exception as e:
print('邮件发送失败:', e)
通过以上步骤,你可以轻松地使用Python发送包含链接、附件和源代码的邮件。实践过程中,确保遵循目标邮箱服务提供商的规定,使用合适的授权码,并在代码中替换关键信息,以保证邮件发送的顺利进行。
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