Answer:
The Python code is given below with appropriate comments
Explanation:
#required method, assuming Volume class is defined and is accessible
def partyVolume(filename):
#opening file in read mode, assuming file exists
file=open(filename,'r')
#reading initial volume
initial=float(file.readline())
#creating a Volume object with initial volume
v=Volume(initial)
#looping through rest of the lines in file
for line in file.readlines():
#removing trailing/leading white spaces/newlines and splitting line by white
#space to get a list of tokens
line=line.strip().split(' ')
#ensuring that length of resultant list is 2
if len(line)==2:
#reading first value as direction (U or D)
dir=line[0].upper()
#reading second value as float value
value=float(line[1])
if dir=='U':
#turning volume up
v.up(value)
elif dir=='D':
#turning volume down
v.down(value)
#closing file, saving changes
file.close()
#returning volume
return v
