title: How to get dtypes of columns in julia dataframe
body: <p>How to get dtypes of all columns and particular column(s) in julia. To be specific what is the pandas equivalent of <code>df.dtypes</code> in julia?</p>
  <p>For example,
  I have a df like below,</p>
  <pre><code>│ Row │ Id    │ name   │ item location │
  │     │ Int64 │ String │ String        │
  ├─────┼───────┼────────┼───────────────┤
  │ 1   │ 1     │ A      │ xyz           │
  │ 2   │ 2     │ B      │ abc           │
  │ 3   │ 3     │ C      │ def           │
  │ 4   │ 4     │ D      │ ghi           │
  │ 5   │ 5     │ E      │ xyz           │
  │ 6   │ 6     │ F      │ abc           │
  │ 7   │ 7     │ G      │ def           │
  │ 8   │ 8     │ H      │ ghi           │
  │ 9   │ 9     │ I      │ xyz           │
  │ 10  │ 10    │ J      │ abc           │
  </code></pre>
  <p>Expected output:</p>
  <pre><code>{'id':  Int64, 'name': String, 'item location': String}
  </code></pre>
  <p>How to get dtypes, i.e., <code>Int64 │ String │ String</code>  in Julia?</p>