readline in while loop

[laotseu]

Geert Fannes wrote:
> hello, i tried to construct a program to read a file, line after line. i 
> have no idea why it does not work...
> 
> f=file("test.txt","r");
> while l=f.readline():
>     print l;
> 
> the problem is with "while l=f.readline():" the next program does work
> 
> f=file("test.txt","r");
> while f.readline():
> 
> i tried things like
> 
> f=file("test.txt","r");
> while (l=f.readline())!="":
>     print l;
> 
> but that doesn't work either. 

It doesn't work because Python is not C. In Python, an assignation is a 
statement, not an expression, so it don't have a value.

You could (should ?) use the 'readlines()' method 
          -
f = file("test.txt", "r")
lines = f.readlines()
f.close()

for line in lines:
     print line


BTW, dont use 'l' as an identifier, unless you want to obfuscate your 
code (but then Python might not be the best language...)

Laotseu