I have code from this Question: Why is Python’s eval() rejecting this multiline string, and how can I fix it?
def multiline_eval(expr, context={}): "Evaluate several lines of input, returning the result of the last line" tree = ast.parse(expr) eval_exprs = [] exec_exprs = [] for module in tree.body: if isinstance(module, ast.Expr): eval_exprs.append(module.value) else: exec_exprs.append(module) exec_expr = ast.Module(exec_exprs, type_ignores=[]) exec(compile(exec_expr, 'file', 'exec'), context) results = [] for eval_expr in eval_exprs: results.append(eval(compile(ast.Expression((eval_expr)), 'file', 'eval'), context)) return 'n'.join([str(r) for r in results])
When I use this code:
multiline_eval(''' print("Hello World1") for a in range(5): print(a) print("Hello World2") ''')
The result is:
0 1 2 3 4 Hello World1 Hello World2
I am expecting this:
Hello World1 0 1 2 3 4 Hello World2
How can I change the code? I tried to change the code, but I was not successful.
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Answer
The code you’ve posted sorts the ast tree body in 2 buckets, the ast.Expr
s and the rest, and then processes them bucket-wise. So, you have to remove the “bucketing”. You could try something like the following:
import ast def multiline_eval(expr, ctx={}): results = [] for node in ast.parse(expr).body: if isinstance(node, ast.Expr): result = eval(compile(ast.Expression(node.value), '<string>', 'eval'), ctx) results.append(result) else: module = ast.Module([node], type_ignores=[]) results.append(exec(compile(module, '<string>', 'exec'), ctx)) return 'n'.join(map(str, results))