title: Pyspark can't convert float to Float :-/
body: <p>I have a pyspark rdd: </p>
  
  <pre><code>proba_classe_0.take(2)
  [0.38030685472943737, 0.34728188900913715]
  </code></pre>
  
  <p>I want to transform on DF : </p>
  
  <pre><code>from pyspark.sql.types import FloatType
  fields = [ StructField('probabilite' , FloatType() ) ]
  schema = StructType(fields)
  df_proba_classe_1 = spark.createDataFrame(proba_classe_1, schema=schema)
  df_proba_classe_1.count()
  </code></pre>
  
  <p>I got a strange error : </p>
  
  <pre><code>TypeError: StructType can not accept object 0.6196931452705625 in type &lt;class 'float'&gt;
  </code></pre>