You should probably create a pipeline that first runs your mapreduce, then runs a pipeline stage that only prepends a header to the header-less csv created from the mapreduce.
On Tue, Mar 5, 2013 at 3:45 PM, Jonas Heyden <[email protected]> wrote: > I am fiddling around with GAE mapreduce and have one question: > > Is it possible to change a variable only for a certain job in mapreduce? > > The reason I am asking is: > > The input csv and output csv of my mapreduce job are supposed to have the > same header row - however, the header row is somewhere in the output csv, > but never at the top. To get the right header row, I inserted a counter into > my reduce function that checks the current iteration of the reduce job and > if it is 0, it will pass the hard-coded header-row to the pipeline. The > counter gets reset when the output csv gets stored in the blobstore. > > The problem: More often than not the counter resets itself randomly, > probably because I had to define it as global variable "reduce_counter = 0" > outside of the function. > > Is there any method to chain a variable/parameter to a job or is there any > better way to get the header_row? > > I don't think that I can work with the DictReader or csv module as the > output is stored in the blobstore and blobstore objects cannot be altered as > far as I know. > > You can find my code on www.github.com/jvdheyden/ste in the main.py > document. > > Thanks! > > > > -- > Jonas von der Heyden > +49 163 2464010 > http://de.linkedin.com/in/jvheyden > > -- > You received this message because you are subscribed to the Google Groups > "Google App Engine" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/google-appengine?hl=en. > For more options, visit https://groups.google.com/groups/opt_out. > > -- Jim -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/google-appengine?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
