I have a program which reads commands from a text file
for example, the command syntax will be as follows and is a string
'index command param1 param2 param3'
The number of parameters is variable from 0 up to 3 index is an integer command is a string all the params are integers
I would like to split them so that I have a list as follows
[index,'command',params[]]
What is the best way to do this?
Thanks
Not sure if it's the best way, but here's one way:
lines = open('file.txt')
for line in lines:
as_list = line.split()
result = [as_list[0], as_list[1], as_list[2:]]
print result
Result will contain
['index', 'command', ['param1', 'param2', 'param3']]
def add_command(index, command, *params):
index = int(index)
#do what you need to with index, command and params here
with open('commands.txt') as f:
for line in f:
add_command(*line.split())
i typically write:
lines = open('a.txt').readlines()
for line in lines:
para = lines.split()
index = int(para[0])
command = para[1]
para1 = float(para[2])
...
f = open(filename) and for line in f:, which avoids reading the whole file into memory.
>>> for line in open("file"):
... line=line.rstrip().split(" ",2)
... line[0]=int(line[0])
... line[2]=line[2].split()
... print line
...
[1, 'command', ['param1', 'param2', 'param3']]
If you use Python 3+, then following should be enough as indicated in PEP 3132: Extended Iterable Unpacking:
(index,command,*parameters) = line.split()
Otherwise, I like solution from James best:
def add_command(index, command, *params):
...
The Answer provided by cb160 is correct and smart way, But, I did it in this way. In cb160's code, Only thing is index should be in Integer format, as you have mentioned.
In my below code, I added exceptions for empty lines in input file if there are any.
#Example Input File: (file content)
"""
1 command1 parm1a parm1b parm1c
2 command2 parm2a parm2b parm2c
3 command3 parm3a parm3b parm3c
"""
li = []
for line in open('list_of_commands.txt'):
try:
lis = line.split()
li.append([int(lis[0]),lis[1], lis[2:]])
except IndexError:
pass # do nothing if empty lines are found
print li
Output
[1, 'command1', ['parm1a', 'parm1b', 'parm1c']]
[2, 'command2', ['parm2a', 'parm2b', 'parm2c']]
[3, 'command3', ['parm3a', 'parm3b', 'parm3c']]
let me know if I missed anything.
Thanks
lin.list_of_commands.txt is actually a string ;).readlines method, as well as producing actual output