For some reason I want this:
a = ['ok.py', 'hello.py']
I want to calculate size of each elements and add all those sizes and store in a single variable:
for i in a:
dest = '/home/zurelsoft/my_files'
fullname = os.path.join(dest, i) #Get the file_full_size to calculate size
st = int(os.path.getsize(fullname))
f_size = size(st)
It does this for every element. How can I add them all?
one method would be to add them to a list and then use sum
sizes = []
for i in a:
dest = '/home/zurelsoft/my_files'
fullname = os.path.join(dest, i) #Get the file_full_size to calculate size
st = int(os.path.getsize(fullname))
f_size = size(st)
sizes.append(f_size)
print sum(sizes)
or you could have a single variable.
sum_size = 0
for i in a:
dest = '/home/zurelsoft/my_files'
fullname = os.path.join(dest, i) #Get the file_full_size to calculate size
st = int(os.path.getsize(fullname))
sum_size += size(st)
print sum_size
or you could keep it in a dictionary....
d = {}
for i in a:
dest = '/home/zurelsoft/my_files'
fullname = os.path.join(dest, i) #Get the file_full_size to calculate size
st = int(os.path.getsize(fullname))
d[i] = size(st)
to get each ones size:
print '\n'.join(['%s: %d' % (k, v) for k, v in d.items()])
to get the sum:
print sum(d.values())
wrapping it all into a function and using a method similar to the one used by Ivo van der Wijk:
def get_file_sizes(parent_dir, files):
import os
return sum([os.path.getsize(os.path.join(parent_dir, f)) for f in files])
calling the function:
a = ['ok.py', 'hello.py']
all_sizes = get_file_sizes('/home/zurelsoft/my_files', a)
+ between a str and an int there is not even an + operator in the code i wrote. maybe you mean the second one. in which case, it means that size() does not return a number, so you should change size() to return a number, or cast with int()
+ operator, in the sum function.You can reduce it to a single sum with generator as follows:
sum(os.path.getsize(os.path.join("/etc", f)) for f in ["passwd", "hosts"])
Basically combining the individual steps you're taking into a single expression that can be passed to sum()
I'm not sure what size() does but you can of course insert that into the expression. Make sure it returns integers and not strings, of course.
/etc, passwd and hosts from? i don't think these paths help the OP. but the answer is indeed correct. dont forget the import os. i would use a dictionary to also store the size for each one. :)
