SyntaxError trying to execute python 3 code with python 2.7

Question

I run the python 3 code which from others code as following in the python 2.7 environment, there is error as following, please give me some hints how to solve it, thanks! If you want more information, please tell me.

python code:

#! /usr/bin/env python

from __future__ import print_function
import argparse
from collections import defaultdict
import numpy as np
import os
import sys
import utils


if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument('target')
    args = parser.parse_args()

    target = defaultdict(list)
    for i, line in enumerate(sys.stdin):
        filename, score, *rect = line.strip().split()
        name, _ = os.path.splitext(filename)
        score = float(score)
        rect = tuple(map(float, rect))
        target[name].append((score, rect))

        if (i + 1) % 1000 == 0:
            print(i + 1, file=sys.stderr)

    for name in target.keys():
        target[name] = np.array(target[name], dtype=utils.dtype)
        target[name].sort(order=('score',))
        target[name][:] = target[name][::-1]

    np.savez_compressed(args.target, **target)

the error:

File "./scripts/lo.py", line 19
    filename, score, *rect = line.strip().split()
                     ^
SyntaxError: invalid syntax

Possible duplicate of Python star unpacking for version 2.7

Matthias
– Matthias

2017-04-19 11:55:47 +00:00
Commented Apr 19, 2017 at 11:55 — Matthias
– Matthias, Commented Apr 19, 2017 at 11:55

Community · Accepted Answer · 2017-05-23 11:46:57Z

8

Extended Iterable Upacking is only available in Python 3.0 and later.

Refer to this question for workarounds.

edited May 23, 2017 at 11:46

CommunityBot

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answered Apr 19, 2017 at 10:37

timgeb

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2 Comments

tktktk0711 Over a year ago

hi @timgeb thanks for your comments, how to solve this problem in python2

timgeb Over a year ago

@tktktk0711 See the second part of my answer.

martineau · Accepted Answer · 2017-04-20 12:26:28Z

2

The script is using something called "Extended Iterable Unpacking" which was added to Python 3.0.
The feature is described in PEP 3132.

To do the same thing in Python 2, replace the problem line:

    filename, score, *rect = line.strip().split()

with these two lines:

    seq = line.strip().split()
    filename, score, rect = seq[0], seq[1], seq[2:]

OR these two:

   seq = line.strip().split()
   (filename, score), rect = seq[:2], seq[2:]

edited Apr 20, 2017 at 12:26

answered Apr 19, 2017 at 12:16

martineau

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