csv empty strings handling and values appending - csv

Question

With a csv of ~50 rows (stars) and ~30 columns (name, magnitudes and distance), that has some empty string values (''), I am trying to do two things in which all the help so far hasn't been useful. (1) I need to parse empty strings as 0.0, so I can (2) append each row in a list of lists (what I called s).
In other words:
- s is a list of stars (each one has all its parameters)
- d is a particular parameter for all the stars (distance), which I obtain correctly.
Big issue is with s. My try:
with open('stars.csv', 'r') as mycsv:
csv_stars = csv.reader(mycsv)
next(csv_stars) #skip header
stars = list(csv_stars)
s = [] # star
d = [] # distances
for row in stars:
row[row==''] = '0'
s.append(float(row)) #stars
d.append(arcsec*AU*float(row[30]))
I can't think of a better syntax, and so I get the error
s.append(float(row)) # stars
TypeError: float() argument must be a string or a number
From s I would obtain later the magnitudes for all the stars, separately. But first things first...

Answer 1

#cwasdwa Please look at below code. it will give you an idea. I am sure there might be better way. This solution is based on what I have understood from your code.
with open('stars.csv', 'r') as mycsv:
csv_stars = csv.reader(mycsv)
next(csv_stars) #skip header
stars = list(csv_stars)
s = [] # star
d = [] # distances
for row in stars:
newRow = [] #create new row array to convert all '' to 0.0
for x in row:
if x =='':
newRow.append(0.0)
else:
newRow.append(x)
s.append(newRow) #stars
if row[30] == '':
value = 0.0
else:
value = row[30]
d.append(arcsec*AU*float(value))