Programming Forums > Script Programming > Python

verb1426 · Aug 14th, 2005, 4:01 PM

بسم الله الرحمن الرحيم
Hi guys

I have designed a program that converts the date from Islamic calendar to Christian calendar.Unfortunately, I have faced a REAL problem (I mean a REAL problem for me as a beginner). First Here is the program:

print " Welcome to date converting program"
print " ------------------------------------"
print
print " Please choose the number for the converting process you wish to perform:"
print
print "1- From Christian calendar to Islamic calendar."
print "2- From Islamic calendar to Christian calendar."
print
a = input ("The number:")
if a == 1:
d = input ("Enter the date:")
g = d - 579
if g <0:
print "The date in the Islamic calendar is" , g - g - g , "BH"
else:
print "The date in the Islamic calendar is" , g , "AH"
elif a == 2:
d = input ("Enter the date:")
print "The date in the Christian calendar is" , d + 579 , "AD"
else:
print "Restart the program and enter the right number."

-------------------------
But as you can see, since there is no GOTO function in Python, I had to write :"Restart the program and enter the right number."

I would appreciate it if anyone could modefy this program or show me how to modefy it so that if I choose a number that is not on the list it returns to the line which says: a = input ("The number:")

Thank you.

Ooble · Aug 14th, 2005, 4:22 PM

First of all, especially when posting Python code, use [ code ] tags. Without them, the webpage eats whitespace.

Secondly, don't use one-letter variables. It makes debugging a bitch.

Onto the code. I've improved it where I could. The trick is to use a loop:

(Toggle Plain Text)

print " Welcome to my Date-Converting Application"
print " -----------------------------------------"
print
print " Please the converting process you wish to perform:"
print
print "  1: From Christian calendar to Islamic calendar."
print "  2: From Islamic calendar to Christian calendar."
print "  0: Exit."
print

a = 42

while a != 0:
	a = input ("Conversion: ")
	if a == 0:
		break
	
	if a == 1:
		d = input ("Enter the date: ")
		g = d - 579
		
		if g < 0:
			print "The date in the Islamic calendar is", g - g - g, "BH"
		else:
			print "The date in the Islamic calendar is", g, "AH"
	
	elif a == 2:
		d = input ("Enter the date: ")
		print "The date in the Christian calendar is", d + 579, "AD"
	
	else:
		print "Not an option, genius."
	
	print

By the way, using a goto function is almost always considered bad programming. There's almost always a better way to do things, unless you're coding in Assembly.

coldDeath · Aug 14th, 2005, 4:37 PM

while he replied i was working on a solution, you need to learn object oriented programming, its a lot funner

(Toggle Plain Text)

class calendarconverter:
	def christiantoislamic(self):
		idate = input("Enter the Christian date:")
		g = idate -579
		if g <0:
			print "The date in the Islamic calendar is" , g - g - g , "BH"
		else:
			print "The date in the Islamic calendar is" , g , "AH"
		
	def islamictochristian(self):
		cdate = input ("Enter the date:")
		print "The date in the Christian calendar is" , cdate + 579 , "AD"
		
	def run(self):
		cal=input("1 or 2:")
		if (cal == 1):
			self.christiantoislamic()
		elif (cal == 2):
			self.islamictochristian()
		else:
			print"Use correct syntax please"
			self.run()
		
calendar = calendarconverter()
calendar.run()

works like a dream

Ooble · Aug 14th, 2005, 4:48 PM

I really didn't feel like teaching him about functions at the same time, let alone classes. :p

Sane · Aug 14th, 2005, 6:00 PM

Holy crap ColdDeath! You're improving quickly!! :eek:

P.S.

Code like this:

print "The date in the Islamic calendar is" , g , "AH"

Can be done with better possibilities like this:

print "The date in the Islamic calendar is %s AH"%( g )

Where %s requests a string, and %d requests an integer. But %s is recommended in all situations even if you have an integer.

And if you are looking to make your program more user friendly, raw_input superceeds input, and then in the condition testing you must make 1 in to "1" or make cal in to str(cal).

Cerulean · Aug 14th, 2005, 6:27 PM

Quote:

And if you are looking to make your program more user friendly, raw_input superceeds input

And if you want to make your program safe. input() calls eval on what it reads, meaning you can do:

(Toggle Plain Text)

>>> import os
>>> input("Enter a number: ")
os.remove("/")
(goodbye computer if you did that as root)

Yes, it's that unsafe.

As for the object-orientated example.. the program gains nothing from the OO. This isn't Java - use OO where it makes sense to do so, not because it looks cool

Sane · Aug 15th, 2005, 12:20 AM

But you can use OO where it helps you expand your practice of the language.

coldDeath · Aug 15th, 2005, 6:24 AM

Quote:

Holy crap ColdDeath! You're improving quickly!!

=) thanks, and i just spent quite a while learning Tkinter, i can do it pretty well now, then i find everyone says wxPython is better :o lol

I must admit though, Tkinter is disgustingly ugly on linux, i mean have you seen the menus it makes (like the File,Edit,View menu). I did a small bit of wxpython and it does look better.

Dietrich · Aug 15th, 2005, 8:07 AM

Quote:

Originally Posted by Cerulean

And if you want to make your program safe. input() calls eval on what it reads, meaning you can do:

(Toggle Plain Text)

>>> import os
>>> input("Enter a number: ")
os.remove("/")
(goodbye computer if you did that as root)

Yes, it's that unsafe.

As for the object-orientated example.. the program gains nothing from the OO. This isn't Java - use OO where it makes sense to do so, not because it looks cool

Too bad input() has never been modified to trap this kind of silliness!

verb1426 · Aug 15th, 2005, 10:08 AM

بسم الله
Actually I don't know how to thank you .....this is very kind of you ......I realize that programming requires cleverness , logical thinking and finally (and most importantly) good knowledge in mathmatics.Such qualities are available in you guys ...but for me, I am ZERO in maths.I can't even tell what 3**4(for instance) is except if I do it on paper or after long thinking ..and even if I know I can't put it in a fruitful program. Can I still become professional with my poor knowledge in maths? I maen gradually?
Thank you for everything.

Aug 14th, 2005, 4:01 PM	#1
verb1426 Newbie Join Date: Aug 2005 Posts: 26 Rep Power: 0	Are there any alternatives for GOTO in Python?I am facing a problem please respond. بسم الله الرحمن الرحيم Hi guys I have designed a program that converts the date from Islamic calendar to Christian calendar.Unfortunately, I have faced a REAL problem (I mean a REAL problem for me as a beginner). First Here is the program: print " Welcome to date converting program" print " ------------------------------------" print print " Please choose the number for the converting process you wish to perform:" print print "1- From Christian calendar to Islamic calendar." print "2- From Islamic calendar to Christian calendar." print a = input ("The number:") if a == 1: d = input ("Enter the date:") g = d - 579 if g <0: print "The date in the Islamic calendar is" , g - g - g , "BH" else: print "The date in the Islamic calendar is" , g , "AH" elif a == 2: d = input ("Enter the date:") print "The date in the Christian calendar is" , d + 579 , "AD" else: print "Restart the program and enter the right number." ------------------------- But as you can see, since there is no GOTO function in Python, I had to write :"Restart the program and enter the right number." I would appreciate it if anyone could modefy this program or show me how to modefy it so that if I choose a number that is not on the list it returns to the line which says: a = input ("The number:") Thank you.

Aug 14th, 2005, 4:22 PM	#2
Ooble I eat cake for breakfast. Join Date: Jul 2004 Location: In my box. Posts: 4,434 Rep Power: 9	First of all, especially when posting Python code, use [ code ] tags. Without them, the webpage eats whitespace. Secondly, don't use one-letter variables. It makes debugging a bitch. Onto the code. I've improved it where I could. The trick is to use a loop: (Toggle Plain Text) print " Welcome to my Date-Converting Application" print " -----------------------------------------" print print " Please the converting process you wish to perform:" print print " 1: From Christian calendar to Islamic calendar." print " 2: From Islamic calendar to Christian calendar." print " 0: Exit." print a = 42 while a != 0: a = input ("Conversion: ") if a == 0: break if a == 1: d = input ("Enter the date: ") g = d - 579 if g < 0: print "The date in the Islamic calendar is", g - g - g, "BH" else: print "The date in the Islamic calendar is", g, "AH" elif a == 2: d = input ("Enter the date: ") print "The date in the Christian calendar is", d + 579, "AD" else: print "Not an option, genius." print print " Welcome to my Date-Converting Application" print " -----------------------------------------" print print " Please the converting process you wish to perform:" print print " 1: From Christian calendar to Islamic calendar." print " 2: From Islamic calendar to Christian calendar." print " 0: Exit." print a = 42 while a != 0: a = input ("Conversion: ") if a == 0: break if a == 1: d = input ("Enter the date: ") g = d - 579 if g < 0: print "The date in the Islamic calendar is", g - g - g, "BH" else: print "The date in the Islamic calendar is", g, "AH" elif a == 2: d = input ("Enter the date: ") print "The date in the Christian calendar is", d + 579, "AD" else: print "Not an option, genius." print By the way, using a goto function is almost always considered bad programming. There's almost always a better way to do things, unless you're coding in Assembly. __________________ Me :: You :: Them

Aug 14th, 2005, 4:37 PM	#3
coldDeath Expert Programmer Join Date: Aug 2005 Location: UK Posts: 862 Rep Power: 3	while he replied i was working on a solution, you need to learn object oriented programming, its a lot funner (Toggle Plain Text) class calendarconverter: def christiantoislamic(self): idate = input("Enter the Christian date:") g = idate -579 if g <0: print "The date in the Islamic calendar is" , g - g - g , "BH" else: print "The date in the Islamic calendar is" , g , "AH" def islamictochristian(self): cdate = input ("Enter the date:") print "The date in the Christian calendar is" , cdate + 579 , "AD" def run(self): cal=input("1 or 2:") if (cal == 1): self.christiantoislamic() elif (cal == 2): self.islamictochristian() else: print"Use correct syntax please" self.run() calendar = calendarconverter() calendar.run() class calendarconverter: def christiantoislamic(self): idate = input("Enter the Christian date:") g = idate -579 if g <0: print "The date in the Islamic calendar is" , g - g - g , "BH" else: print "The date in the Islamic calendar is" , g , "AH" def islamictochristian(self): cdate = input ("Enter the date:") print "The date in the Christian calendar is" , cdate + 579 , "AD" def run(self): cal=input("1 or 2:") if (cal == 1): self.christiantoislamic() elif (cal == 2): self.islamictochristian() else: print"Use correct syntax please" self.run() calendar = calendarconverter() calendar.run() works like a dream

Aug 14th, 2005, 4:48 PM	#4
Ooble I eat cake for breakfast. Join Date: Jul 2004 Location: In my box. Posts: 4,434 Rep Power: 9	I really didn't feel like teaching him about functions at the same time, let alone classes. :p __________________ Me :: You :: Them

Aug 14th, 2005, 6:00 PM	#5
Sane Programming Guru Join Date: Apr 2005 Posts: 1,799 Rep Power: 5	Holy crap ColdDeath! You're improving quickly!! :eek: P.S. Code like this: print "The date in the Islamic calendar is" , g , "AH" Can be done with better possibilities like this: print "The date in the Islamic calendar is %s AH"%( g ) Where %s requests a string, and %d requests an integer. But %s is recommended in all situations even if you have an integer. And if you are looking to make your program more user friendly, raw_input superceeds input, and then in the condition testing you must make 1 in to "1" or make cal in to str(cal). __________________ Waterloo's Canadian Computing Competition (CCC) - Stage 2 Problems, Solutions, and Test Data

Aug 15th, 2005, 12:20 AM	#7
Sane Programming Guru Join Date: Apr 2005 Posts: 1,799 Rep Power: 5	But you can use OO where it helps you expand your practice of the language. __________________ Waterloo's Canadian Computing Competition (CCC) - Stage 2 Problems, Solutions, and Test Data

Aug 15th, 2005, 10:08 AM	#10
verb1426 Newbie Join Date: Aug 2005 Posts: 26 Rep Power: 0	بسم الله Actually I don't know how to thank you .....this is very kind of you ......I realize that programming requires cleverness , logical thinking and finally (and most importantly) good knowledge in mathmatics.Such qualities are available in you guys ...but for me, I am ZERO in maths.I can't even tell what 3*4(for instance) is except if I do it on paper or after long thinking ..and even if I know I can't put it in a fruitful program. Can I still become professional with my poor knowledge in maths? I maen gradually? Thank you for everything. __________________ www.islam.ws Last edited by verb1426; Aug 15th, 2005 at 10:37 AM.*

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Programming Forums > Script Programming > Python

Are there any alternatives for GOTO in Python?I am facing a problem please respond.