Question

我正在尝试创建一个脚本，在为其提供开始和结束日期之后生成日期范围。

例如：

start = 2016-01-01

结束= 2017-10-01

脚本将输出如下列表：

['2016-01-01 2016-04-01'，

2016-04-01 2016-07-01'，

'2016-07-01 2016-10-01'，

'2016-10-01 2017-01-01'，

'2017-01-01 2017-04-01'，

'2017-04-01 2017-07-01'，

'2017-07-01 2017-10-01']

到目前为止，我已经设法生成了所有必要的时间范围，但是我无法将每个日期分组到这些时间范围所需的时间格式。

到目前为止，这是我的代码

start = '2016-01-01'
end = str(pd.to_datetime('today').replace(day=1))[:10]
dates = list(pd.date_range(start, end, freq="3MS"))
new_dates = []
for i in dates:
    i= str(i)[:10]
    new_dates.append(i)

输出： `

['2016-01-01',
 '2016-04-01',
 '2016-07-01',
 '2016-10-01',
 '2017-01-01',
 '2017-04-01',
 '2017-07-01',
 '2017-10-01']

如果有人帮助我完成脚本的最后一部分，我非常感激。

Answer 1

使用dates数组，删除带dates[:-1]的最后一个元素，删除第一个元素dates[1:]，然后column_stack两个数组：

import numpy as np

start = '2016-01-01'
end = pd.to_datetime('today').replace(day=1)
dates = pd.date_range(start, end, freq="3MS").strftime('%Y-%m-%d')

np.column_stack((dates[:-1], dates[1:]))
#array([['2016-01-01', '2016-04-01'],
#       ['2016-04-01', '2016-07-01'],
#       ['2016-07-01', '2016-10-01'],
#       ['2016-10-01', '2017-01-01'],
#       ['2017-01-01', '2017-04-01'],
#       ['2017-04-01', '2017-07-01'],
#       ['2017-07-01', '2017-10-01']], 
#      dtype='<U10')

要获得每个范围的条目，我们可以添加它们：

np.char.add(np.char.add(dates[:-1], ' '), dates[1:])
#array(['2016-01-01 2016-04-01', '2016-04-01 2016-07-01',
#       '2016-07-01 2016-10-01', '2016-10-01 2017-01-01',
#       '2017-01-01 2017-04-01', '2017-04-01 2017-07-01',
#       '2017-07-01 2017-10-01'], 
#      dtype='<U21')

Answer 2

添加numpy free替代

@property (strong, nonatomic) CNContactViewController *contactViewController;
@property (assign, nonatomic) UIBarStyle saveAppearanceBarStyle;
@property (strong, nonatomic) UIColor *saveAppearanceBarTintColor;
@property (strong, nonatomic) UIColor *saveAppearanceTintColor;
@property (strong, nonatomic) UIColor *saveAppearanceBackgroundColor;
@property (strong, nonatomic) NSDictionary<NSAttributedStringKey, id> * saveAppearanceTitleTextAttributes;
@property (assign, nonatomic) BOOL saveAppearanceTranslucent;


- (IBAction)onAddToContactsButtonTapped:(id)sender

    self.contactViewController = [CNContactViewController viewControllerForUnknownContact: ... ]; // as before

    [self suspendNavBarAppearanceSettings];

    UINavigationController *popNav = [[UINavigationController alloc] initWithRootViewController:self.contactViewController];
    popNav.modalPresentationStyle = UIModalPresentationPopover;

    UIBarButtonItem *doneButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(onAddToContactsDoneTapped:)];
    self.contactViewController.navigationItem.leftBarButtonItem = doneButton;

    [self presentViewController:popNav animated:YES completion:nil];

    UIPopoverPresentationController *popoverController = newNav.popoverPresentationController;
    popoverController.permittedArrowDirections = UIPopoverArrowDirectionAny;
    popoverController.sourceRect = ...;  // where you want it to point
    popoverController.sourceView = ...;  // where you want it to point
    popoverController.delegate = self;
}

- (void) suspendNavBarAppearanceSettings
{
    self.saveAppearanceBarStyle = [UINavigationBar appearance].barStyle;
    self.saveAppearanceBarTintColor = [UINavigationBar appearance].barTintColor;
    self.saveAppearanceTintColor = [UINavigationBar appearance].tintColor;
    self.saveAppearanceBackgroundColor = [UINavigationBar appearance].backgroundColor;
    self.saveAppearanceTitleTextAttributes = [UINavigationBar appearance].titleTextAttributes;
    self.saveAppearanceTranslucent = [UINavigationBar appearance].translucent;

    [UINavigationBar appearance].barStyle = UIBarStyleDefault;
    [UINavigationBar appearance].barTintColor = nil;
    [UINavigationBar appearance].tintColor = nil;
    [UINavigationBar appearance].backgroundColor = nil;
    [UINavigationBar appearance].titleTextAttributes = nil;
    [UINavigationBar appearance].translucent = YES;
}

- (void) restoreNavBarAppearanceSettings
{
    [UINavigationBar appearance].barStyle = self.saveAppearanceBarStyle;
    [UINavigationBar appearance].barTintColor = self.saveAppearanceBarTintColor;
    [UINavigationBar appearance].tintColor = self.saveAppearanceTintColor;
    [UINavigationBar appearance].backgroundColor = self.saveAppearanceBackgroundColor;
    [UINavigationBar appearance].titleTextAttributes = self.saveAppearanceTitleTextAttributes;
    [UINavigationBar appearance].translucent = self.saveAppearanceTranslucent;
}

- (void)onAddToContactsDoneTapped:(id)sender
{
    [self restoreNavBarAppearanceSettings];

    [[self presentedViewController] dismissViewControllerAnimated:YES completion:nil];
}

 #pragma mark - CNContactViewControllerDelegate

 - (void)contactViewController:(CNContactViewController *)viewController
        didCompleteWithContact:(nullable CNContact *)contact
 {
    [self restoreNavBarAppearanceSettings];

    [[self presentedViewController] dismissViewControllerAnimated:YES completion:nil];
 }

#pragma mark - UIPopoverPresentationControllerDelegate

- (void)prepareForPopoverPresentation:(UIPopoverPresentationController *)popoverPresentationController
{
    // This method is only called if we are presented in a popover, i.e. on iPad
    // as opposed to full screen like on a phone.

    // on iPad you just tap outside to finish, so remove the Done button
    self.contactViewController.navigationItem.leftBarButtonItem = nil;
}

- (void)popoverPresentationControllerDidDismissPopover:(UIPopoverPresentationController *)popoverPresentationController
{
    [self restoreNavBarAppearanceSettings];
}

这里需要注意的是，它的执行速度大约是@Psidom提供的第一个import pandas as pd start = '2016-01-01' end = pd.to_datetime('today').replace(day=1) dates = pd.date_range(start, end, freq="3MS").strftime('%Y-%m-%d') coupled_dates = [] for date in zip(*(dates[:-1], dates[1:])): coupled_dates.append(' '.join(date)) coupled_dates解决方案的两倍。当采取＆＃34; propper＆＃34;第二个版本，numpy执行比python差3倍。

优势在于，如果您无法访问numpy / datetime，则很可能会将此解决方案与标准pandas模块一起使用。

Answer 3

在分别删除第一个和最后一个元素后，您可以先将两个单独的列表合并到一个元组列表中（根据@Psidom的答案）：

dates1 = dates[:-1]
dates2 = dates[1:]

这将生成两个列表，其中dates1缺少原始列表中的最后一个元素，dates2缺少原始列表的第一个元素。

dates3 = zip(dates1, dates2)

这将在dates3中生成一个像这样的结构：

[('2016-01-01', '2016-04-01'), ('2016-04-01', '2016-07-01'), ...]

现在您可以生成所需输出字符串的列表，如下所示：

output = [x + ' ' + y for x,y in dates3]

您也可以将所有这些写入一行，但可能会损害可读性：

output = [x + ' ' + y for x,y in zip(dates[:-1], dates[1:])]

Answer 4

import pandas as pd
a = pd.date_range("20160101","20171001", freq="3MS") # given date range
b =a.map(str).map(lambda x: x[:10]) # to_string and take 10 characters 
c = b[:-1]+" "+b[1:] # shift the index array and join strings
d = c.tolist() # cast to python's list if you need

带有pandas的日期范围

4 个答案: