title: Data Lost while creating bins using python pandas cut function
body: <p>My objective is to transfer one column from df1 to df2 and at the same time creating bins.I have dataframe named df1 which include 3 numerical variables. I want to fetch one variable named 'tenure' to df2 and want to create bins.It transfer column values to df2 but df2 shows some missing values.
  please find code below :</p>
  
  <pre><code>df2=pd.cut(df1["tenure"] , bins=[0,20,60,80], labels=['low','medium','high'])
  </code></pre>
  
  <p>before creating df2 I checked for missing values in df1. there was not such mussing values but after creating bins it shows 11 missing values.</p>
  
  <pre><code>print(df2.isnull().sum())
  </code></pre>
  
  <p>Above Code shows 11 missing values</p>
  
  <p>Anyones help is appreciated.</p>