evaluating a string

[piet]

JH> Okay, sorry about that. How embarassing. Perhaps I should code before opening
JH> my mouth, huh? Anycase, here is a baby implementation of a string evaluator
JH> that doesn't get hung up on integer division.
JH> ... splittext = re.split("/", text)
JH> ... text2 = ""
JH> ... for i in range(len(splittext)-1):
JH> ... text2 = text2 + splittext[i] + ".0/"
JH> ... text2 = text2 + splittext[-1]
JH> ... return eval(text2)
JH> ...

string_eval("1+2*3/4")

JH> 2.5
If you want to have fractional answers then you should also accept
fractional input. So what about
"1+2*3.6/4"

[Joal Heagney]

Okay, sorry about that. How embarassing. Perhaps I should code before opening
my mouth, huh? Anycase, here is a baby implementation of a string evaluator
that doesn't get hung up on integer division.
... splittext = re.split("/", text)
... text2 = ""
... for i in range(len(splittext)-1):
... text2 = text2 + splittext[i] + ".0/"
... text2 = text2 + splittext[-1]
... return eval(text2)
...

string_eval("1+2*3/4")

2.5
Joal Heagney/AncientHart

[Joal Heagney]

On Tue, 17 Oct 2000 04:01:24 GMT, prakash.ojha at hope.edu

I am new to Python and would like to know how can I evaluate a string
like "1+2*3/4" to give a numeric result. Is there any built in
function that will give me this result. Any help would be greatly
appreciated.

Since this is Python, the answer won't surprise you: the builtin

eval("1+2*3/4")

2
Anticipating what may be your next question, the reason that it
doesn't give you 2.5 is that in Python, division of integers produces
an integer result.
Regards,
Matt

eval("%s""1+2*3/4" 1.0)

*grins*
Joal Heagney/AncientHart

Hmm. Well that was wierd. It kinda worked on something similar, but when I
tried it on the above string to check *shrugs*. This one works, but I don't

eval("1+2*3/4"".0")

Perhaps a regular expression???

Joal Heagney/AncientHart

[Matthew Dixon Cowles]

On Tue, 17 Oct 2000 04:01:24 GMT, prakash.ojha at hope.edu

I am new to Python and would like to know how can I evaluate a string
like "1+2*3/4" to give a numeric result. Is there any built in
function that will give me this result. Any help would be greatly
appreciated.

Since this is Python, the answer won't surprise you: the builtin

eval("1+2*3/4")

2

Anticipating what may be your next question, the reason that it
doesn't give you 2.5 is that in Python, division of integers produces
an integer result.

Regards,
Matt

[Joal Heagney]

On Tue, 17 Oct 2000 04:01:24 GMT, prakash.ojha at hope.edu

I am new to Python and would like to know how can I evaluate a string
like "1+2*3/4" to give a numeric result. Is there any built in
function that will give me this result. Any help would be greatly
appreciated.

Since this is Python, the answer won't surprise you: the builtin

eval("1+2*3/4")

2
Anticipating what may be your next question, the reason that it
doesn't give you 2.5 is that in Python, division of integers produces
an integer result.
Regards,
Matt

eval("%s""1+2*3/4" 1.0)

*grins*

Joal Heagney/AncientHart

[Joal Heagney]

Post by piet
JH> Okay, sorry about that. How embarassing. Perhaps I should code before opening
JH> my mouth, huh? Anycase, here is a baby implementation of a string evaluator
JH> that doesn't get hung up on integer division.
JH> ... splittext = re.split("/", text)
JH> ... text2 = ""
JH> ... text2 = text2 + splittext[i] + ".0/"
JH> ... text2 = text2 + splittext[-1]
JH> ... return eval(text2)
JH> ...

string_eval("1+2*3/4")

JH> 2.5
If you want to have fractional answers then you should also accept
fractional input. So what about
"1+2*3.6/4"
--
Piet van Oostrum <piet at cs.uu.nl>
URL: http://www.cs.uu.nl/~piet [PGP]
Private email: P.van.Oostrum at hccnet.nl

Yikes. *grins* How about

Post by piet

import re

... splittext = re.split("/", text)
... text2 =""
... for i in range(len(splittext) - 1):
... text2 = text2 + splittext[i] + "* 1.0/"
... text2 = text2 + splittext[-1]
... return eval(text2)
...

Post by piet

string_eval("1+2*3/4")

2.5

Post by piet

string_eval("1+2*3.6/4")

2.8

Joal Heagney/AncientHart

[prakash.ojha]

I am new to Python and would like to know how can I evaluate a string
like "1+2*3/4" to give a numeric result. Is there any built in function
that will give me this result. Any help would be greatly appreciated.


Sent via Deja.com http://www.deja.com/
Before you buy.