ValueError:无法将字符串转换为float:'花瓣长度'（机器学习示例）

Question

我运行下面链接的示例代码来创建一个模型，并用iris数据集进行验证。在

http://machinelearningmastery.com/machine-learning-in-python-step-by-step/

在上面的链接中，他们使用了在线数据集，并且运行良好。在

我下载了csv格式的iris数据集，并在linuxbox中运行了相同的程序，但是它抛出了以下错误。在

Traceback (most recent call last): File "/home/nn/Desktop/iris.py", line 44, in <module> cv_results = model_selection.cross_val_score(model, X_train, Y_train, cv=kfold, scoring=scoring) File "/home/nn/.local/lib/python3.5/site-packages/sklearn/model_selection/_validation.py", line 140, in cross_val_score for train, test in cv_iter) File "/home/nn/.local/lib/python3.5/site-packages/sklearn/externals/joblib/parallel.py", line 758, in __call__ while self.dispatch_one_batch(iterator): File "/home/nn/.local/lib/python3.5/site-packages/sklearn/externals/joblib/parallel.py", line 608, in dispatch_one_batch self._dispatch(tasks) File "/home/nn/.local/lib/python3.5/site-packages/sklearn/externals/joblib/parallel.py", line 571, in _dispatch job = self._backend.apply_async(batch, callback=cb) File "/home/nn/.local/lib/python3.5/site-packages/sklearn/externals/joblib/_parallel_backends.py", line 109, in apply_async result = ImmediateResult(func) File "/home/nn/.local/lib/python3.5/site-packages/sklearn/externals/joblib/_parallel_backends.py", line 326, in __init__ self.results = batch() File "/home/nn/.local/lib/python3.5/site-packages/sklearn/externals/joblib/parallel.py", line 131, in __call__ return [func(*args, **kwargs) for func, args, kwargs in self.items] File "/home/nn/.local/lib/python3.5/site-packages/sklearn/externals/joblib/parallel.py", line 131, in <listcomp> return [func(*args, **kwargs) for func, args, kwargs in self.items] File "/home/nn/.local/lib/python3.5/site-packages/sklearn/model_selection/_validation.py", line 238, in _fit_and_score estimator.fit(X_train, y_train, **fit_params) File "/home/nn/.local/lib/python3.5/site-packages/sklearn/linear_model/logistic.py", line 1173, in fit order="C") File "/home/nn/.local/lib/python3.5/site-packages/sklearn/utils/validation.py", line 521, in check_X_y ensure_min_features, warn_on_dtype, estimator) File "/home/nn/.local/lib/python3.5/site-packages/sklearn/utils/validation.py", line 382, in check_array array = np.array(array, dtype=dtype, order=order, copy=copy) ValueError: could not convert string to float: 'Petal.Length'

Answer 1

你能检查一下当你用read_csv读取数据时你是否忽略了标题？ 您可以在读取csv中使用：

header='infer'