file find skips first letter

[Wanderer]

I'm using code

    def getFiles(self, fileBase):
        """return a list of the filenames in a director containing a
base word
        """

        allFiles = os.listdir(self.resultDir)
        baseFiles = []
        for f in allFiles:
            if f.find(fileBase) > 0:
                baseFiles.append(f)

        return baseFiles

but the code can't find files with fileBase in it if the fileBase
starts the filename.

if the filenames are rnoise##.tif and fileBase is "rnoise" the file
won't be found. If fileBase is "noise" the files will be found.