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Sep 21st, 2009

a simple math problem

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hi all,

i have a file that contains the following data (just a sample) :

Python Syntax (Toggle Plain Text)
 0 	 0.932 0.933 0.931 0.931 0.929 0.933 0.93 0.928 
 1 	 0.974 0.98 0.978 0.976 0.974 0.974 
 2 	 0.953 0.949 0.944 0.951 0.942 0.942 0.942 0.948 
 3 	 0.933 0.934 0.934 0.935 0.931 0.933 0.932 0.934 
 4 	 0.939 0.934 0.934 0.934 0.937 0.932 0.938 
 5 	 0.944 0.942 0.942 0.943 0.939 0.95 0.942 0.948 
 6 	 0.974 0.976 0.974 0.971 0.97 0.967 0.971 0.974 
 7 	 0.986 0.984 0.984 0.986 0.986 0.984 
 0 	 0.927 0.933 0.931 0.931 0.929 0.933 0.93 0.928 
 1 	 0.974 0.98 0.978 0.976 0.973 0.971 0.974 
 2 	 0.953 0.949 0.951 0.942 0.942 0.942 0.948 
 3 	 0.933 0.934 0.934 0.935 0.931 0.933 0.932 0.931 
 4 	 0.939 0.934 0.934 0.932 0.937 0.932 0.938 
 5 	 0.944 0.942 0.942 0.943 0.939 0.95 0.95 0.948 
 6 	 0.974 0.974 0.974 0.971 0.97 0.967 0.971 0.974 
 7 	 0.986 0.984 0.984 0.986 0.984 0.986
 0 	 0.932 0.933 0.931 0.931 0.929 0.933 0.93 0.928 
 1 	 0.974 0.98 0.978 0.976 0.974 0.974 
 2 	 0.953 0.949 0.944 0.951 0.942 0.942 0.942 0.948 
 3 	 0.933 0.934 0.934 0.935 0.931 0.933 0.932 0.934 
 4 	 0.939 0.934 0.934 0.934 0.937 0.932 0.938 
 5 	 0.944 0.942 0.942 0.943 0.939 0.95 0.942 0.948 
 6 	 0.974 0.976 0.974 0.971 0.97 0.967 0.971 0.974 
 7 	 0.986 0.984 0.984 0.986 0.986 0.984 
 0 	 0.927 0.933 0.931 0.931 0.929 0.933 0.93 0.928 
 1 	 0.974 0.98 0.978 0.976 0.973 0.971 0.974 
 2 	 0.953 0.949 0.951 0.942 0.942 0.942 0.948 
 3 	 0.933 0.934 0.934 0.935 0.931 0.933 0.932 0.931 
 4 	 0.939 0.934 0.934 0.932 0.937 0.932 0.938 
 5 	 0.944 0.942 0.942 0.943 0.939 0.95 0.95 0.948 
 6 	 0.974 0.974 0.974 0.971 0.97 0.967 0.971 0.974 
 7 	 0.986 0.984 0.984 0.986 0.984 0.986

and i parse it using the following commands :

Python Syntax (Toggle Plain Text)
file_hol = open("<file_name>.dat", "r")
data_hol = []
for line_hol in file_hol :
	line_hol = [float(x) for x in line_hol.split()]
	data_hol.append(tuple(line_hol))
file_hol.close()
file_hol = open("<file_name>.dat", "r")
data_hol = []
for line_hol in file_hol :
	line_hol = [float(x) for x in line_hol.split()]
	data_hol.append(tuple(line_hol))
file_hol.close()

so, i get a list of lists with the name data_hol (everything is ok till now)

the 1st column is a timestamp
the 2nd column is a port number
what i would like to find is the port with the largest sum of the numbers of the rest of the columns
and, eventually, to have a list of ports where a port corresponds to a list of the port number and and the numbers (rest of the columns) with the largest sum,
so

Python Syntax (Toggle Plain Text)
pisa_hol = [0]
for i in range(0, len(data_hol)) :
	if sum(data_hol[i][2:len(data_hol[i])]) > sum(pisa_hol[int(data_hol[i][1])][1:len(pisa_hol[int(data_hol[i][1])])]) :		pisa_hol[data_hol[i][1]] = data_hol[i][2, len(data_hol[i])]
pisa_hol = [0]
for i in range(0, len(data_hol)) :
	if sum(data_hol[i][2:len(data_hol[i])]) > sum(pisa_hol[int(data_hol[i][1])][1:len(pisa_hol[int(data_hol[i][1])])]) :		pisa_hol[data_hol[i][1]] = data_hol[i][2, len(data_hol[i])]

what i get is "TypeError: len() of unsized object"

any ideas ?

thanx

Last edited by OneDreamCloser; Sep 21st, 2009 at 1:56 pm.

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OneDreamCloser

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Sep 21st, 2009

Re: a simple math problem

It's hard to help you without the full traceback of the error but here's my two cents:

You're parsing the file contents incorrectly. What you should be doing is splitting each line at the tab character to get time stamp, port number, then the remaining string of floats. At this point you can sum the floats together and get a single float for your data list.

Here's how I would parse the data you provided:

python Syntax (Toggle Plain Text)
>>> data_stor = []
>>> for line in file_hol:
...     data = line.split('\t')
...     if len(data) == 3:
...         tstamp = data[0].strip()
...         port = data[1].strip()
...         valu = sum([float(ea) for ea in data[2].strip().split()])
...         data_stor.append([tstamp, port, valu])
...     
>>> max(data_stor, key=lambda x:x[2])
['501', '6', 7.7770000000000001]
>>>
>>> data_stor = []
>>> for line in file_hol:
...     data = line.split('\t')
...     if len(data) == 3:
...         tstamp = data[0].strip()
...         port = data[1].strip()
...         valu = sum([float(ea) for ea in data[2].strip().split()])
...         data_stor.append([tstamp, port, valu])
...     
>>> max(data_stor, key=lambda x:x[2])
['501', '6', 7.7770000000000001]
>>>

This returns that port 6 at timestamp 501 has the highest sum of numbers.

Last edited by jlm699; Sep 21st, 2009 at 2:42 pm.

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Sep 21st, 2009

Re: a simple math problem

Something like that might do. I avoided the use of float() until the end to keep time-stamp and port info from turning into floats:

python Syntax (Toggle Plain Text)
raw_data = """\
501 	 0 	 0.932 0.933 0.931 0.931 0.929 0.933 0.93 0.928
501 	 1 	 0.974 0.98 0.978 0.976 0.974 0.974
501 	 2 	 0.953 0.949 0.944 0.951 0.942 0.942 0.942 0.948
501 	 3 	 0.933 0.934 0.934 0.935 0.931 0.933 0.932 0.934
501 	 4 	 0.939 0.934 0.934 0.934 0.937 0.932 0.938
501 	 5 	 0.944 0.942 0.942 0.943 0.939 0.95 0.942 0.948
501 	 6 	 0.974 0.976 0.974 0.971 0.97 0.967 0.971 0.974
501 	 7 	 0.986 0.984 0.984 0.986 0.986 0.984
502 	 0 	 0.927 0.933 0.931 0.931 0.929 0.933 0.93 0.928
502 	 1 	 0.974 0.98 0.978 0.976 0.973 0.971 0.974
502 	 2 	 0.953 0.949 0.951 0.942 0.942 0.942 0.948
502 	 3 	 0.933 0.934 0.934 0.935 0.931 0.933 0.932 0.931
502 	 4 	 0.939 0.934 0.934 0.932 0.937 0.932 0.938
502 	 5 	 0.944 0.942 0.942 0.943 0.939 0.95 0.95 0.948
502 	 6 	 0.974 0.974 0.974 0.971 0.97 0.967 0.971 0.974
502 	 7 	 0.986 0.984 0.984 0.986 0.984 0.986"""
 
fname = "my_data.dat"
# write the test file
fout = open(fname, "w")
fout.write(raw_data)
fout.close()
 
# read the test file
fin = open(fname, "r")
data_hol = []
for line_hol in fin:
    line_hol = [x for x in line_hol.split() ]
    data_hol.append(tuple(line_hol))
 
my_datalist = []
for line in data_hol:
    #print(line[1], line[2:])  # test
    port = line[1]
    # now you can use float()
    data_sum = sum([float(x) for x in line[2:]])
    my_datalist.append((port, data_sum))
 
# test the list of (port, data_sum) tuples
for tup in my_datalist:
    print(tup)
 
"""my output -->
('0', 7.4470000000000001)
('1', 5.8559999999999999)
('2', 7.5709999999999997)
('3', 7.4660000000000002)
('4', 6.548)
('5', 7.5500000000000007)
('6', 7.7770000000000001)
('7', 5.9099999999999993)
('0', 7.4420000000000002)
('1', 6.8260000000000005)
('2', 6.6270000000000007)
('3', 7.4630000000000001)
('4', 6.5460000000000003)
('5', 7.5579999999999998)
('6', 7.7749999999999995)
('7', 5.9099999999999993)
"""
raw_data = """\
501 	 0 	 0.932 0.933 0.931 0.931 0.929 0.933 0.93 0.928
501 	 1 	 0.974 0.98 0.978 0.976 0.974 0.974
501 	 2 	 0.953 0.949 0.944 0.951 0.942 0.942 0.942 0.948
501 	 3 	 0.933 0.934 0.934 0.935 0.931 0.933 0.932 0.934
501 	 4 	 0.939 0.934 0.934 0.934 0.937 0.932 0.938
501 	 5 	 0.944 0.942 0.942 0.943 0.939 0.95 0.942 0.948
501 	 6 	 0.974 0.976 0.974 0.971 0.97 0.967 0.971 0.974
501 	 7 	 0.986 0.984 0.984 0.986 0.986 0.984
502 	 0 	 0.927 0.933 0.931 0.931 0.929 0.933 0.93 0.928
502 	 1 	 0.974 0.98 0.978 0.976 0.973 0.971 0.974
502 	 2 	 0.953 0.949 0.951 0.942 0.942 0.942 0.948
502 	 3 	 0.933 0.934 0.934 0.935 0.931 0.933 0.932 0.931
502 	 4 	 0.939 0.934 0.934 0.932 0.937 0.932 0.938
502 	 5 	 0.944 0.942 0.942 0.943 0.939 0.95 0.95 0.948
502 	 6 	 0.974 0.974 0.974 0.971 0.97 0.967 0.971 0.974
502 	 7 	 0.986 0.984 0.984 0.986 0.984 0.986"""

fname = "my_data.dat"
# write the test file
fout = open(fname, "w")
fout.write(raw_data)
fout.close()

# read the test file
fin = open(fname, "r")
data_hol = []
for line_hol in fin:
    line_hol = [x for x in line_hol.split() ]
    data_hol.append(tuple(line_hol))

my_datalist = []
for line in data_hol:
    #print(line[1], line[2:])  # test
    port = line[1]
    # now you can use float()
    data_sum = sum([float(x) for x in line[2:]])
    my_datalist.append((port, data_sum))

# test the list of (port, data_sum) tuples
for tup in my_datalist:
    print(tup)

"""my output -->
('0', 7.4470000000000001)
('1', 5.8559999999999999)
('2', 7.5709999999999997)
('3', 7.4660000000000002)
('4', 6.548)
('5', 7.5500000000000007)
('6', 7.7770000000000001)
('7', 5.9099999999999993)
('0', 7.4420000000000002)
('1', 6.8260000000000005)
('2', 6.6270000000000007)
('3', 7.4630000000000001)
('4', 6.5460000000000003)
('5', 7.5579999999999998)
('6', 7.7749999999999995)
('7', 5.9099999999999993)
"""

sneekula

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Sep 21st, 2009

Re: a simple math problem

thank you all, what i really needed was the max. sum for every port,
your comments were very helpful

the final version is :

Python Syntax (Toggle Plain Text)
pisa_hol = {}
file_hol = open("/.../hol.dat", "r")
data_hol = []
for line_hol in file_hol :
	data_hol = line_hol.split('\t')
	if len(data_hol) == 3 :
		port = int(data_hol[1].strip())
		cells = [float(x) for x in data_hol[2].strip().split()]
		weight = sum(cells)
		if pisa_hol.has_key(port) :
			if sum(pisa_hol[port]) < sum(cells) :
				pisa_hol[port] = cells
		else :
			pisa_hol[port] = cells
	else :
		print "ERROR : Input data are NOT formated properly !"
pisa_hol = {}
file_hol = open("/.../hol.dat", "r")
data_hol = []
for line_hol in file_hol :
	data_hol = line_hol.split('\t')
	if len(data_hol) == 3 :
		port = int(data_hol[1].strip())
		cells = [float(x) for x in data_hol[2].strip().split()]
		weight = sum(cells)
		if pisa_hol.has_key(port) :
			if sum(pisa_hol[port]) < sum(cells) :
				pisa_hol[port] = cells
		else :
			pisa_hol[port] = cells
	else :
		print "ERROR : Input data are NOT formated properly !"

Last edited by OneDreamCloser; Sep 21st, 2009 at 11:15 pm.

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Sep 23rd, 2009

Re: a simple math problem

hi again,

given that

Python Syntax (Toggle Plain Text)
 0 	 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 
 1 	 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 
 2 	 0.0 0.0 0.0 0.0 0.0 0.965 0.0 0.0 
 3 	 0.0 0.952 0.0 0.951 0.949 0.0 0.0 0.947 
 4 	 0.965 0.0 0.963 0.0 0.0 0.0 0.962 0.0 
 5 	 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 
 6 	 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 
 7 	 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 
 0 	 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 
 1 	 0.0 0.0 0.98 0.0 0.0 0.979 0.0 0.0 
 2 	 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 
 3 	 0.947 0.0 0.0 0.945 0.0 0.0 0.0 0.0 
 4 	 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 
 5 	 0.0 0.965 0.0 0.0 0.0 0.0 0.964 0.0
 0 	 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 
 1 	 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 
 2 	 0.0 0.0 0.0 0.0 0.0 0.965 0.0 0.0 
 3 	 0.0 0.952 0.0 0.951 0.949 0.0 0.0 0.947 
 4 	 0.965 0.0 0.963 0.0 0.0 0.0 0.962 0.0 
 5 	 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 
 6 	 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 
 7 	 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 
 0 	 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 
 1 	 0.0 0.0 0.98 0.0 0.0 0.979 0.0 0.0 
 2 	 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 
 3 	 0.947 0.0 0.0 0.945 0.0 0.0 0.0 0.0 
 4 	 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 
 5 	 0.0 0.965 0.0 0.0 0.0 0.0 0.964 0.0

and that

Python Syntax (Toggle Plain Text)
cells = [float(x) for x in data_hol[2].strip().split()]
cells = [float(x) for x in data_hol[2].strip().split()]

where data_hol[2] is the 3rd column of the a file, that contains a batch of floats,
HOW can i insert into the list "cells" only the NON-zero items ?

OneDreamCloser

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Sep 23rd, 2009

Re: a simple math problem

Click to Expand / Collapse Quote originally posted by OneDreamCloser ...

Python Syntax (Toggle Plain Text)
cells = [float(x) for x in data_hol[2].strip().split()]
cells = [float(x) for x in data_hol[2].strip().split()]
where data_hol[2] is the 3rd column of the a file, that contains a batch of floats,
HOW can i insert into the list "cells" only the NON-zero items ?

If you want to ignore the items that are 0.0:

python Syntax (Toggle Plain Text)
cells = [float(x) for x in data_hol[2].strip().split() if x != 
'0.0']
cells = [float(x) for x in data_hol[2].strip().split() if x != 
'0.0']

Keep in mind however that the ports with all 0.0 will result in an empty list named cells , which potentially could break other code. Just ensure that your list handling is going to account for the possibility of empty lists.

Last edited by jlm699; Sep 23rd, 2009 at 3:08 pm.

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Sep 23rd, 2009

Re: a simple math problem

thank you

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