Problems using apply

[m-roper]

Hi,
I want to apply a function to all rows of a column. I want to raise an exception if a certain condition is met.
In pandas, I use the apply function.
I tried to use the apply function in vaex but I encountered a strange difficulty: I get a Key error. In my example, I just want the ValueError to be raised so that my unit tests work properly. What am I doing wrong?

Thank you!

Input file: text.txt (includes lines in between -----------------)

X
1

Code:
import vaex
df = vaex.from_csv("./text.txt",sep="\t",header=0)
def func(x):
if x>=1:
raise ValueError(F"{x} >= 1")
df.X.apply(func,multiprocessing=False)

Output:
Traceback (most recent call last):
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/scopes.py", line 113, in evaluate
result = self[expression]
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/scopes.py", line 198, in getitem
raise KeyError("Unknown variables or column: %r" % (variable,))
KeyError: "Unknown variables or column: 'lambda_function(X)'"

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/dataframe.py", line 2273, in data_type
data = self.evaluate(expression, 0, 1, filtered=False, array_type=array_type, parallel=False)
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/dataframe.py", line 3095, in evaluate
return self._evaluate_implementation(expression, i1=i1, i2=i2, out=out, selection=selection, filtered=filtered, array_type=array_type, parallel=parallel, chunk_size=chunk_size, progress=progress)
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/dataframe.py", line 6562, in _evaluate_implementation
value = block_scope.evaluate(expression)
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/scopes.py", line 119, in evaluate
result = eval(expression, expression_namespace, self)
File "", line 1, in
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/arrow/numpy_dispatch.py", line 136, in wrapper
result = f(*args, **kwargs)
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/expression.py", line 1612, in call
return vaex.multiprocessing.apply(self._apply, args, kwargs, self.multiprocessing)
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/multiprocessing.py", line 40, in apply
return f(args, **kwargs)
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/expression.py", line 1627, in _apply
scalar_result = self.f([fix_type(k[i]) for k in args], **{key: value[i] for key, value in kwargs.items()})
File "", line 3, in func
ValueError: 1 >= 1

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/scopes.py", line 113, in evaluate
result = self[expression]
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/scopes.py", line 198, in getitem
raise KeyError("Unknown variables or column: %r" % (variable,))
KeyError: "Unknown variables or column: 'lambda_function(X)'"

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "", line 1, in
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/expression.py", line 815, in repr
return self.repr_plain()
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/expression.py", line 845, in repr_plain
dtype = self.dtype
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/expression.py", line 506, in dtype
return self.df.data_type(self)
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/dataframe.py", line 2275, in data_type
data = self.evaluate(expression, 0, 1, filtered=True, array_type=array_type, parallel=False)
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/dataframe.py", line 3095, in evaluate
return self._evaluate_implementation(expression, i1=i1, i2=i2, out=out, selection=selection, filtered=filtered, array_type=array_type, parallel=parallel, chunk_size=chunk_size, progress=progress)
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/dataframe.py", line 6562, in _evaluate_implementation
value = block_scope.evaluate(expression)
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/scopes.py", line 119, in evaluate
result = eval(expression, expression_namespace, self)
File "", line 1, in
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/arrow/numpy_dispatch.py", line 136, in wrapper
result = f(*args, **kwargs)
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/expression.py", line 1612, in call
return vaex.multiprocessing.apply(self._apply, args, kwargs, self.multiprocessing)
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/multiprocessing.py", line 40, in apply
return f(args, **kwargs)
File "/home/m/miniconda3/envs/srablast/lib/python3.8/site-packages/vaex/expression.py", line 1627, in _apply
scalar_result = self.f([fix_type(k[i]) for k in args], **{key: value[i] for key, value in kwargs.items()})
File "", line 3, in func
ValueError: 1 >= 1