catching with changes

gpextras.py

@@ -0,0 +1,77 @@
+##############################################################################
+# (C) Copyright 2014, 2015 William W. Cohen.  All rights reserved.
+##############################################################################
+
+from guineapig import *
+
+class ReadCSV(Reader):
+    """ Returns the lines in a CSV file, converted to Python tuples."""
+
+    def __init__(self,src,**kw):
+        Reader.__init__(self,src)
+        self.kw = kw
+
+    def rowGenerator(self):
+        for tup in csv.reader(sys.stdin,**self.kw):
+            yield tup
+
+    def __str__(self):
+        return 'ReadCVS("%s",%s)' % (self.src,str(self.kw)) + self.showExtras()
+
+class ReadBlocks(Reader):
+    """ Returns blocks of non-empty lines, separated by empty lines"""
+
+    def __init__(self,src,isEndBlock=lambda line:line=="\n"):
+        Reader.__init__(self,src)
+        self.isEndBlock = isEndBlock
+
+    def rowGenerator(self):
+        buf = []
+        for line in sys.stdin:
+            if self.isEndBlock(line):
+                yield buf
+                buf = []
+            else:
+                buf.append(line)
+        if buf:
+            yield buf
+
+    def __str__(self):
+        return 'ReadBlocks("%s")' % self.src + self.showExtras()
+
+class Log(ReplaceEach):
+    """Print logging messages to stderr as data is processed. 
+    For every row, the logfun will be called with arguments
+    logfun(rowValue,rowIndex).
+    """
+
+    def __init__(self, inner=None, logfun=lambda rowV,rowI:None):
+        self.rowNum = 0
+        def logfunCaller(rowValue):
+            self.rowValue += 1
+            self.logfun(rowValue,self.rowNum)
+            return rowValue
+        ReplaceEach.__init__(self,inner,by=logfunCaller)
+
+    def __str__(self):
+        return 'Log("%s")' % self.src + self.showExtras()
+
+class LogEchoFirst(Log):
+
+    """Echo the first N things."""
+
+    def __init__(self, inner=None, first=10):
+        def logfirst(rowValue,rowIndex):
+            if rowIndex<=first:
+                print >> sys.stderr, 'row %d: "%s"' % (rowIndex,rowValue)
+        Log.__init__(self, inner=inner, logfun=logfirst)
+
+class LogProgress(Log):
+
+    """Echo a status message every 'interval' rows."""
+
+    def __init__(self, inner=None, msg="Logging progress", interval=1000):
+        def logprogress(rowValue,rowIndex):
+            if (rowIndex % interval)==0:
+                print >> sys.stderr, "%s: %d rows done" % (msg,rowIndex)
+        Log.__init__(self, inner=inner, logfun=logprogress)