Re: basic output question

2008-01-25 Thread Alan Isaac 
John Deas wrote: 
 My problem is that f.read() outputs nothing

Since ``open`` did not give you an IOError,
you did get a handle to the files,
so this suggests that the files you read
are empty...

Alan Isaac
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Re: basic output question

2008-01-25 Thread Wildemar Wildenburger 
John Deas wrote:
 Hi, I am very new to Python (1 evening...)
 I need to process a series of files (toto-1.txt toto-2.txt toto-3.txt
 toto-4.txt), and as such I created a small program to go through the
 files in a directory. I want to call the script with arguments, like
 
 python script.py toto- 1 1 4
 
 my script is as follow :
 
 import sys
 sys.argv
 header= sys.argv[1]
 start =eval(sys.argv[2])
 step  =eval(sys.argv[3])
 nbit  =eval(sys.argv[4])
 
Style note: You should probably use int() instead of eval. Not only is 
this safer (as in security), it is also safer (as in robust), because it 
will throw an error early if you feed it something other than an int.


 for i in range(nbit):
   filename=header+str(start+i*step)+'.txt'
   f=open(filename,'r')
   f.read()
   f.close()
 
 My problem is that f.read() outputs nothing, and should I print
 filename, I can check that they are well formed, and the files sits in
 the same directory as my script.
 
f.read() spills the text into nothingness. You may want to write its 
output to a variable. ;)

/W
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basic output question

2008-01-25 Thread John Deas 
Hi, I am very new to Python (1 evening...)
I need to process a series of files (toto-1.txt toto-2.txt toto-3.txt
toto-4.txt), and as such I created a small program to go through the
files in a directory. I want to call the script with arguments, like

python script.py toto- 1 1 4

my script is as follow :

import sys
sys.argv
header= sys.argv[1]
start =eval(sys.argv[2])
step  =eval(sys.argv[3])
nbit  =eval(sys.argv[4])

for i in range(nbit):
filename=header+str(start+i*step)+'.txt'
f=open(filename,'r')
f.read()
f.close()

My problem is that f.read() outputs nothing, and should I print
filename, I can check that they are well formed, and the files sits in
the same directory as my script.

Anyone could help me on this ?
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