Pandas - 数据框对象不可调用。（python 2）

Question

我有以下代码：

df(df.Sex=='male')

我收到一条错误，指出dataframe对象不可调用。

我该如何解决这个问题？

Answer 1

它被称为boolean indexing，仅需要df[df.Sex=='male'] ：

df.query("Sex =='male'")

或者：

function ViewModel() {
  var self = this;

  self.Dropdown1 = ko.observableArray();
  self.SelectedItem1 = ko.observable();

  self.Dropdown2 = ko.computed(function() {
    if (self.SelectedItem1() == null) {
      return [];
    };
    console.log(ko.toJS(self.SelectedItem1()))
    return self.SelectedItem1().Submenu;
  });

  self.SelectedItem2 = ko.observable();

  self.LoadDropDown = function() {
    self.Dropdown1.push({
      "Name": "Hat",
      "Value": "top",
      "Submenu": [{
          "Name": "Blue",
          "Value": "#0000FF"
        },
        {
          "Name": "Green",
          "Value": "#00FF00"
        },
        {
          "Name": "Red",
          "Value": "#FF0000"
        }
      ]
    });
    self.Dropdown1.push({
      "Name": "Shirt",
      "Value": "middle",
      "Submenu": [{
          "Name": "Striped",
          "Value": "Striped"
        },
        {
          "Name": "Logo",
          "Value": "Logo"
        },
        {
          "Name": "Plain",
          "Value": "None"
        }
      ]
    });
    self.Dropdown1.push({
      "Name": "Pants",
      "Value": "bottom",
      "Submenu": [{
          "Name": "Jeans",
          "Value": "Jeans"
        },
        {
          "Name": "Kakhis",
          "Value": "Kakhis"
        },
        {
          "Name": "Cordroy",
          "Value": "Cordroy"
        }
      ]
    });
  }
  self.LoadDropDown();


}

ko.applyBindings(new ViewModel());