graphing columns from a CSV that includes null values- python -

i relatively new python , running lot of issues. trying create graph using 2 columns csv file contains many null values. there way convert null value 0 or delete row contains null values in columns?

your question asked underspecified, think if pick concrete example, should able figure out how adapt actual use case.

so, let's values either string representation of float, or empty string representing null:

a,b 1.0,2.0 2.0, ,3.0 4.0,5.0 

and let's you're reading using csv.reader, , you're explicitly handling rows 1 one do_stuff_with function:

with open('foo.csv') f:     next(reader) # skip header     row in csv.reader(f):         a, b = map(float, row)         do_stuff_with(a, b) 

now, if want treat null values 0.0, need replace float function returns float(x) non-empty x, , 0.0 empty x:

def nullable_float(x):     return float(x) if x else 0.0  open('foo.csv') f:     next(reader) # skip header     row in csv.reader(f):         a, b = map(nullable_float, row)         do_stuff_with(a, b) 

if want skip rows contain null value in column b, check column b before doing conversion:

with open('foo.csv') f:     next(reader) # skip header     row in csv.reader(f):         if not row[1]:             continue         a, b = map(nullable_float, row)         do_stuff_with(a, b)