New to Programming: Adding custom functions with ipynotify classes

Dave Angel davea at
Fri Apr 3 14:12:38 CEST 2015

On 04/03/2015 07:37 AM, Steven D'Aprano wrote:
> On Fri, 3 Apr 2015 12:30 pm, Saran A wrote:
>> #This helper function returns the length of the file
>> def file_len(f):
>>      with open(f) as f:
>>          for i, l in enumerate(f):
>>              pass
>>              return i + 1
> Not as given it doesn't. It will raise an exception if the file cannot be
> opened, and it will return 1 for any file you can read.
> After you fix the incorrect indentation, the function is horribly
> inefficient. Instead, use this:
> import os
> os.stat(filename).st_size

No, he actually wants the number of records in the file.  So he still 
needs to read the whole file.

Naturally I figured that out from the phrase in the spec:
    "indicating the total number of records processed"
not from the comment in the code.


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