how to get the length of a number

[Stan Cook]

Can anyone tell me how to get the length of a number. I
know len(string) will get the length of a string, but it
doesn't like len(int). I seem to remember something like %s
string. I tried to set a variable = to %s int, but that
doesn't work. Is there a function I've forgotten about to
convert an integer to a string?

Regards

Stan

 

[Saketh]

Can anyone tell me how to get the length of a number. I
know len(string) will get the length of a string, but it
doesn't like len(int). I seem to remember something like %s
string. I tried to set a variable = to %s int, but that
doesn't work. Is there a function I've forgotten about to
convert an integer to a string?

Regards

Stan

Use str(int). Then use len(). For example, len(str(12345)) will give
you 5.

 

[Fredrik Lundh]

Is there a function I've forgotten about to convert an
> integer to a string?

str(value)

</F>

 

[Stan Cook]

Use str(int). Then use len(). For example, len(str(12345)) will give
you 5.

Ahhhh! How could I have forgotten that. Boy is my face red

Thanks....

I'll try to make my next question a more intelligent one.

Regards,

Stan

 

[Sybren Stuvel]

Felipe Almeida Lessa enlightened us with:

To see how many decimal digits it has:

import math
math.ceil(math.log(i, 10))

That doesn't work properly.
5.0

But "10000" certainly has as much digits as "10001".

Sybren

 

[Felipe Almeida Lessa]

Em Dom, 2006-06-11 às 20:10 +0000, Stan Cook escreveu:

Can anyone tell me how to get the length of a number. I
know len(string) will get the length of a string, but it
doesn't like len(int). I seem to remember something like %s
string. I tried to set a variable = to %s int, but that
doesn't work. Is there a function I've forgotten about to
convert an integer to a string?

To convert an integer i to a string:

str(i) or "%s" % i


To see how many decimal digits it has:

import math
math.ceil(math.log(i, 10))

 

[Claudio Grondi]

Can anyone tell me how to get the length of a number. I know
len(string) will get the length of a string, but it doesn't like
len(int). I seem to remember something like %s string. I tried to set
a variable = to %s int, but that doesn't work. Is there a function I've
forgotten about to convert an integer to a string?

Regards

Stan

len('%s'%(1234567,)) gives 7
len('%s'%(1234**45,)) and len(str(1234**45))
give 140

Claudio

 

[Fredrik Lundh]

Hmmm, you're right.

math.floor(math.log(x, 10)) + 1

x = 0

</F>

 

[Felipe Almeida Lessa]

Em Dom, 2006-06-11 às 13:17 -0700, Saketh escreveu:

Use str(int). Then use len(). For example, len(str(12345)) will give
you 5.

$ python2.4 -mtimeit -s 'x=12345' 'len(str(x))' 1000000 loops, best of
3: 1.33 usec per loop
$ python2.4 -mtimeit -s 'x=12345;from math import ceil,log' 'ceil(log(x,
10))'
1000000 loops, best of 3: 1.54 usec per loop
$ python2.4 -mtimeit -s 'x=12345**123' 'len(str(x))' 1000 loops, best of
3: 209 usec per loop
$ python2.4 -mtimeit -s 'x=12345**123;from math import ceil,log'
'ceil(log(x, 10))'
1000000 loops, best of 3: 1.55 usec per loop
$ python2.4 -mtimeit -s 'x=12345**1234' 'len(str(x))' 100 loops, best of
3: 19.2 msec per loop
$ python2.4 -mtimeit -s 'x=12345**1234;from math import ceil,log'
'ceil(log(x, 10))'
1000000 loops, best of 3: 1.53 usec per loop

 

[Felipe Almeida Lessa]

Em Dom, 2006-06-11 às 22:33 +0200, Sybren Stuvel escreveu:

Felipe Almeida Lessa enlightened us with:

That doesn't work properly.

5.0

But "10000" certainly has as much digits as "10001".

Hmmm, you're right.

math.floor(math.log(x, 10)) + 1

 

[Cameron Laird]

.
.
.

math.floor(math.log(x, 10)) + 1

.... and you're restricting to the positive integers, I take it?
I still have rounding problems: ... return math.floor(math.log(x, 10)) + 1
... 8.0

While modest mollification improves these results, it's going
to be tough to beat len(str(x)).