title: python pandas json_normalize in 1.0.0 with meta path specified - expects iterable
body: <p>I have the data</p>
  
  <pre><code>[{"state": "Florida",
           "shortname": "FL",
           "info": {"governor": "Rick Scott"},
           "counties": [{"name": "Dade",
                         "population": 12345,
                         "Attributes": [
                           {
                            "capture_date": "2020-01-29",
                            "Spirit_code": "TRLQR",
                            "value": 1
                           },
                           {
                              "capture_date": "2020-01-29",
                              "Spirit_code": "HAVPN",
                              "value": 57000
                          }
  
                         ]},
                         {"name": "Broward",
                          "population": 40000,
                           "Attributes": [
                           {
                              "capture_date": "2020-01-29",
                              "Spirit_code": "GMSTP",
                              "value": 14
                          },
                          {
                              "capture_date": "2020-01-29",
                              "Spirit_code": "GWTPN",
                              "value": 11212
                          }
                         ]
                         },
                         {"name": "Palm Beach",
                          "population": 60000,
                          "Attributes": [{
                              "capture_date": "2020-01-29",
                              "Spirit_code": "YGHMN",
                              "value": 154.01
                          },
                          {
                              "capture_date": "2020-01-29",
                              "Spirit_code": "CXZASD",
                              "value": 154.01
                          }]
                         }
           ]},
          {"state": "Ohio",
           "shortname": "OH",
           "info": {"governor": "John Kasich"},
           "counties": [{"name": "Summit", "population": 1234,
                        "Attributes": [{
                              "capture_date": "2020-01-29",
                              "Spirit_code": "QWERTY",
                              "value": 154.01
                          },
                          {
                              "capture_date": "2020-01-29",
                              "Spirit_code": "JKLGH",
                              "value": 154.01
                          }]
           },
                        {"name": "Cuyahoga", "population": 1337,
                        "Attributes": [{
                              "capture_date": "2020-01-29",
                              "Spirit_code": "ASDF",
                              "value": 154.01
                          },
                          {
                              "capture_date": "2020-01-29",
                              "Spirit_code": "POIUY",
                              "value": 154.01
                          }]
  
                        }],
          }
  ]
  </code></pre>
  
  <p>And I am looking for the result:</p>
  
  <pre><code>state,   shortname, name,       population, attirbute.capture_date, attirbute.spirit_code, attirbute.value
  florida, FL        ,Dade,       12345     , 2020-0-29             , TRLQR                , 1
  florida, FL        ,Dade,       12345     , 2020-0-29             , HAVPN                , 57000
  florida, FL        ,Broward,    40000     , 2020-0-29             , GMSTP                , 14
  florida, FL        ,Broward,    40000     , 2020-0-29             , GWTPN                , 11212
  florida, FL        ,Palm Beach, 60000     , 2020-0-29             , YGHMN                , 154.01
  florida, FL        ,Palm Beach, 60000     , 2020-0-29             , YGHMN                , 154.01
  florida, FL        ,Palm Beach, 60000     , 2020-0-29             , CXZASD                , 154.01
  </code></pre>
  
  <p>Basically normalizing for the key attributes in the nested json. Key: "Attributes". </p>
  
  <pre><code>json_normalize(data["data"], ["counties", "Attributes"], ["state", "shortname", ["counties", "name"], ["counties", "population"]])
  </code></pre>
  
  <p>I am getting error: </p>
  
  <pre><code>TypeError: {'name': 'Dade', 'population': 12345, 'Attributes': [{'capture_date': '2020-01-29', 'Spirit_code': 'TRLQR', 'value': 1}, {'capture_date': '2020-01-29', 'Spirit_code': 'HAVPN', 'value': 57000}]} has non iterable value 12345 for path ['population']. Must be iterable or null.
  </code></pre>
  
  <p>but if I run :</p>
  
  <pre><code>plots_in = json_normalize(data["data"], ["counties", "Attributes"],
                     ["state", "shortname", ["counties", "name"]])
  </code></pre>
  
  <p>I get the result:</p>
  
  <pre><code>  capture_date Spirit_code     value    state shortname counties.name
  0   2020-01-29       TRLQR      1.00  Florida        FL          Dade
  1   2020-01-29       HAVPN  57000.00  Florida        FL          Dade
  2   2020-01-29       GMSTP     14.00  Florida        FL       Broward
  3   2020-01-29       GWTPN  11212.00  Florida        FL       Broward
  4   2020-01-29       YGHMN    154.01  Florida        FL    Palm Beach
  5   2020-01-29      CXZASD    154.01  Florida        FL    Palm Beach
  6   2020-01-29      QWERTY    154.01     Ohio        OH        Summit
  7   2020-01-29       JKLGH    154.01     Ohio        OH        Summit
  8   2020-01-29        ASDF    154.01     Ohio        OH      Cuyahoga
  9   2020-01-29       POIUY    154.01     Ohio        OH      Cuyahoga
  </code></pre>
  
  <p>is there something to do with the integer value in the population key?
  because if I run the following then still I am getting the same error:</p>
  
  <pre><code>plots_in = json_normalize(data["data"], ["counties", "population"])
  </code></pre>
  
  <p>Please explain, if someone knows what is going on underneath? </p>