[Re] Checking each item in m.group()?

[nospam@nospam.com]

Hello

I need to go through each line of a CSV file, and extract some fields
using a regex. Then, I need to check each retrieved field, and if it
looks like "", turn this into NULL so that it's correct SQL.

I tried a few things, but still can't it working:
========
#Second field might be empty -> ""
#"Col1",""
#"Col1","Col2"
p = re.compile('^"(.+?)","(.*?)"$')

for line in textlines:
	m = p.search(line)
	if m:
		#Check each column : if '', then turn into NULL

		"""
		for col in line:
			if col == "":
				col = "NULL"
		"""

		"""
		for col in m.group():
			if col == "":
				col="NULL"
		"""

		"""
		for col in m.group(0):
			if col == "":
				col="NULL"
		"""

		"""
		for i in range (0,len(line)):
			if line[i] == "":
				line[i]="NULL"
		"""

		"""
		for i in range(1,len(m.group(0))):
			if m.group(i) == "":
				m.group(i)="NULL"
		"""
		
		sql = "INSERT INTO mytable (col1, col2) VALUES
('%s','%s')" % (m.group(1),m.group(2))
		print sql
f.close()
========

Does someone know the correct syntax?

Thank you.