Question

我有这个脚本：

#!/usr/bin/python
import sys
import ast

def main(argv):
  for line in sys.stdin:
    try:
      rules, scores = line.split('\t')
      scores = ast.literal_eval(scores)
      print '\t'.join([rules, str(any(scores))])
    except:
      sys.stderr.write('Got line ' + line)
      raise

if __name__ == "__main__":
  main(sys.argv[0]) # 0 as there are no args besides the hive query fields

该脚本按预期的输入预期工作

$ echo -e "[{2,3},{4,3}]\t[1]" | ./check_anom.py
[{2,3},{4,3}]   True

但是当输入错误时：

$ echo -e "[{2,3},{4,3}]\t" | ./check_anom.py
Got line [{2,3},{4,3}]
Traceback (most recent call last):
  File "./check_anom.py", line 19, in <module>
    main(sys.argv[0]) # 0 as there are no args besides the hive query fields
  File "./check_anom.py", line 12, in main
    scores = ast.literal_eval(scores)
  File "/usr/lib/python2.7/ast.py", line 49, in literal_eval
    node_or_string = parse(node_or_string, mode='eval')
  File "/usr/lib/python2.7/ast.py", line 37, in parse
    return compile(source, filename, mode, PyCF_ONLY_AST)
  File "<unknown>", line 1

    ^
SyntaxError: unexpected EOF while parsing

我本来会期望出现ValueError，为什么会出现SyntaxError？

Answer 1

您似乎正在尝试eval("")，因为您的[1]所在的\t后面没有split。它在您的第一个命令中，而不是引发错误的命令。

加薪不会引起语法错误，eval("")会导致语法错误，加薪只会引发它。

'raise'引起SyntaxError

1 个答案: