Re: function return

[Fredrik Lundh]

Beema Shafreen wrote:

I have a script using functions , I have a problem in returning the
result. My script returns only one line , i donot know where the looping
is giving problem, Can any one suggest, why this is happening and let me
know how to return all the lines

def get_ptm():
fh = open('file.txt', 'r')
data_lis = []
for line in fh.readlines():
data = line.strip().split('\t')
id = data[0].strip()
gene_symbol = data[1].strip()
ptms = data[8].strip()
result = "%s\t%s\t%s" %(id,gene_symbol,ptms)
return result

note that you put the "return" statement inside the loop, so returning
only one line is the expected behaviour.

result = "%s\t%s\t%s" %(id,gene_symbol,ptms)
data_lis.append(result)

and then return the list when done:

fh.close()

return data_lis

:::

if you change the original return to "yield", the function will turn
into a "generator" that yields one result at a time.

result = "%s\t%s\t%s" %(id,gene_symbol,ptms)
yield result

for more on generators, and how they are used, see the documentation.

</F>