[Tutor] bits taken by variable type

alan.gauld@bt.com alan.gauld@bt.com
Tue, 18 Jun 2002 17:59:58 +0100


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>  Coming from a C++ view point, how do you know if a variable in Python is

>  unsigned long int or some other modified variable type?   
 
In practice, why would you care?
 
> How do you know how much precision a number is stored at?   
 
For integers it is
 
import sys
print sys.maxint
 
If you need longer than maxint use long integers which are arbitrarily
large(effectively)
 
For floats, I'm not sure. Just assume they are big enough and catch
exceptions 
for when they aren't.
 
These are the kind of low level details that Python is trying to shield from
you.
 
Alan G.
 

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<DIV><FONT face=Arial><FONT size=2><SPAN class=580310017-18062002><FONT 
face="Courier New" color=#0000ff>&gt; &nbsp;</FONT></SPAN>Coming from a C++ view 
point, how do you know if a variable in Python is&nbsp;<SPAN 
class=580310017-18062002><FONT face="Courier New" 
color=#0000ff>&nbsp;</FONT></SPAN></FONT></FONT></DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN class=580310017-18062002><FONT 
face="Courier New" color=#0000ff>&gt; </FONT>&nbsp;</SPAN>unsigned long int or 
some other modified variable type?&nbsp;&nbsp;<SPAN 
class=580310017-18062002><FONT face="Courier New" 
color=#0000ff>&nbsp;</FONT></SPAN></FONT></FONT></DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN 
class=580310017-18062002></SPAN></FONT></FONT>&nbsp;</DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN class=580310017-18062002>In practice, 
why would you care?</SPAN></FONT></FONT></DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN 
class=580310017-18062002></SPAN></FONT></FONT>&nbsp;</DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN 
class=580310017-18062002>&gt;</SPAN></FONT></FONT><FONT face=Arial><FONT 
size=2><SPAN class=580310017-18062002>&nbsp;</SPAN>How do you 
know&nbsp;</FONT></FONT><FONT face=Arial><FONT size=2>how much precision a 
number is stored at?&nbsp;&nbsp;<SPAN class=580310017-18062002><FONT 
face="Courier New" color=#0000ff>&nbsp;</FONT></SPAN></FONT></FONT></DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN 
class=580310017-18062002></SPAN></FONT></FONT>&nbsp;</DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN class=580310017-18062002>For integers 
it is</SPAN></FONT></FONT></DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN 
class=580310017-18062002></SPAN></FONT></FONT>&nbsp;</DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN class=580310017-18062002>import 
sys</SPAN></FONT></FONT></DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN class=580310017-18062002>print 
sys.maxint</SPAN></FONT></FONT></DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN 
class=580310017-18062002></SPAN></FONT></FONT>&nbsp;</DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN class=580310017-18062002>If you need 
longer than maxint use long integers which are arbitrarily 
large(effectively)</SPAN></FONT></FONT></DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN 
class=580310017-18062002></SPAN></FONT></FONT>&nbsp;</DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN class=580310017-18062002>For floats, 
I'm not sure. Just assume they are big enough and catch exceptions 
</SPAN></FONT></FONT></DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN class=580310017-18062002>for when they 
aren't.</SPAN></FONT></FONT></DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN 
class=580310017-18062002></SPAN></FONT></FONT>&nbsp;</DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN class=580310017-18062002>These are the 
kind of low level details that Python is trying to shield from 
you.</SPAN></FONT></FONT></DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN 
class=580310017-18062002></SPAN></FONT></FONT>&nbsp;</DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN class=580310017-18062002>Alan 
G.</SPAN></FONT></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT>&nbsp;</DIV></BODY></HTML>

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