Changeset 31949 for trunk/ippToPsps/jython/fits.py

Timestamp:

Jul 29, 2011, 9:53:42 AM (15 years ago)

Author:

rhenders

Message:

added comments and improved some logging

File:

• trunk/ippToPsps/jython/fits.py (modified) (4 diffs)

trunk/ippToPsps/jython/fits.py

@@ -22 +22 @@
        self.localDir = self.doc.find("localOutPath").text
 
-       # does it exist?
+       # does this file even exist?
        if not os.path.isfile(self.originalPath): 
-           self.logger.error("Cannot read file at '" + self.originalPath + "'")
+           self.logger.errorPair("Cannot read file", self.originalPath)
            return
 
+       # ok, we have a file, now copy it locally to save on NFS overhead
        self.logger.infoPair("FITS file", self.originalPath)
        self.localCopyPath = self.localDir + "/temp.fits"
        shutil.copy2(self.originalPath, self.localCopyPath)
 
+       # open the local copy and parse the ridiculou plain-text header
        self.file = open(self.localCopyPath)
        self.header = self.parseHeader()
        self.logger.infoPair("FITS local copy", self.localCopyPath)
        self.logger.infoPair("FITS primary header", "%d cards found" % len(self.header))
+
+       # move file pointer back to the start of the file
        self.rewindToStart()
 
     '''
-    Returns the path to this FITS file
+    Returns the path to the LOCAL COPY of this FITS file
     '''
     def getPath(self):
@@ -58 +62 @@
 
 
+    '''
+    Moves the file pointer back to the start of this file
+    '''
     def rewindToStart(self):
         self.file.seek(0, 0)
@@ -63 +70 @@
 
     '''
-    Finds and reads a header extension
+    Finds and reads a header extension.
+
+    2880 is the magic number that the FITS format uses to break up data: extensions always begin on multiples of 2880 bytes
     '''
     def findAndReadHeader(self, name):
@@ -91 +100 @@
 
             self.file.seek(origIndex, 0)
-            self.logger.error("...could not read header in extension '" + name + "'")
+            self.logger.errorPair("Could not read header", name)
             return
-    #else: self.logger.info("...read header at '" + name + "' and found " + str(len(header)) + " header cards") 
+        else: 
+            self.logger.debug("...read header at '" + name + "' and found " + str(len(header)) + " header cards") 
 
         return header