Your if
statement is always false and T
gets initialized only if a condition is met, so the code doesn’t reach the point where T
gets a value (and by that, gets defined/bound). You should introduce the variable in a place that always gets executed.
Try:
def temp_sky(lreq, breq):
T = <some_default_value> # None is often a good pick
for line in tfile:
data = line.split()
if abs(float(data[0])-lreq) <= 0.1 and abs(float(data[1])-breq) <= 0.1:
T = data[2]
return T