Python选择有条件的元组

Question

let spacing: CGFloat = 10

func addLabels(attributesArray: [String], testResultsDictionary: [String: Float]) {
    var previousContainer: UIView?   // rather than using the index to look up the view for the previous container, just have a variable to keep track of the previous one for you.

    for attribute in attributesArray {
        let container = UIView()
        container.backgroundColor = UIColor.lightGrayColor() // just so I can see it
        container.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(container)

        // set top anchor for container to superview if no previous container, otherwise link it to the previous container

        if previousContainer == nil {
            container.topAnchor.constraintEqualToAnchor(view.topAnchor, constant: spacing).active = true
        } else {
            container.topAnchor.constraintEqualToAnchor(previousContainer!.bottomAnchor, constant: spacing).active = true
        }
        previousContainer = container

        // set leading/trailing constraints for container to superview

        NSLayoutConstraint.activateConstraints([
            container.leadingAnchor.constraintEqualToAnchor(view.leadingAnchor, constant: spacing),
            view.trailingAnchor.constraintEqualToAnchor(container.trailingAnchor, constant: spacing),
        ])

        // create label

        let label = UILabel()
        label.translatesAutoresizingMaskIntoConstraints = false
        label.text = attribute
        container.addSubview(label)

        // create slider

        let slider = UISlider()
        slider.translatesAutoresizingMaskIntoConstraints = false
        slider.value = testResultsDictionary[attribute]!
        container.addSubview(slider)

        // constraints for label and slider

        NSLayoutConstraint.activateConstraints([
            label.topAnchor.constraintEqualToAnchor(container.topAnchor, constant: spacing),
            slider.topAnchor.constraintEqualToAnchor(label.bottomAnchor, constant: spacing),
            container.bottomAnchor.constraintEqualToAnchor(slider.bottomAnchor, constant: spacing),

            label.leadingAnchor.constraintEqualToAnchor(container.leadingAnchor, constant: spacing),
            slider.leadingAnchor.constraintEqualToAnchor(container.leadingAnchor, constant: spacing),

            container.trailingAnchor.constraintEqualToAnchor(label.trailingAnchor, constant: spacing),
            container.trailingAnchor.constraintEqualToAnchor(slider.trailingAnchor, constant: spacing)
        ])
    }
}

我有这样的数据框。我想问一下如何选择或创建一个只有UIStackView的数据框子集，以便结果如下所示？

   module_category    component_category    year_month_sale    year_month_repair 
0              M6                P16          200709            200904   
1              M2                P30          200709            200908   
2              M1                P12          200610            200802   
3              M1                P30          200605            200707   
4              M3                P06          200708            200712

Answer 1

尝试.loc[]方法：

df.loc[df.year_month_repair >= '200802']

其中df是您的数据框

Answer 2

Pythons filter（）对此非常适合：

condition = lambda x: x[3] >= 200802
filteredDataframe = filter(condition, dataframe)

我认为这个代码块不言自明：

• 创建了一个带有lambda的匿名函数，以应用于每个元组
• filter应用该函数并返回所有返回true的元组