string find mystery

Sean DiZazzo half.italian at gmail.com
Thu Sep 3 07:45:20 CEST 2009


On Sep 2, 10:10 pm, Helvin <helvin... at gmail.com> wrote:
> Hi,
>
> I have come across this very strange behaviour. Check this code:
>
>         if file_str.find('Geometry'):
>         #if file_str.endswith('Data_Input_Geometry.txt'):
>             print 'I found geometry'
>         elif file_str.find('Material'):
>             print 'I found material'
> The amazing thing is when file_str  = 'C:\Qt\SimLCM\Default
> \Data_Input_Material.txt',
> the first if statement if fulfilled, that seemingly says that in this
> file_str, python actually finds the word 'Geometry'.
> I know this, because the line: 'I found geometry' is printed. However,
> if instead of using file_str.find(), I use file_str.endswith(), it
> does not exhibit this strange behaviour.
>
> Obviously, I want the elif line to be true, instead of the first if
> statement.
>
> Does anyone know why this is happening?
> Help much appreciated!
>
> Very puzzled,
> Helvin

string.find() returns the index at which the given word is found
within the string.  If the string is not found it returns -1.  So, no
matter what you do, string.find() will evaluate to "True"

You could use it like this:  if file_str.find("Geometry") != -1:

but you probably want to use: if "Geometry" in file_str:

~Sean



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