我试图获得本周的星期一。这在我的表格视图中被视为一周的第一天。 我还需要获得本周的周日。在我的表格视图中，这被视为一周的最后一天。
目前的尝试：
>>> import csv
>>> with open('test.txt') as csvfile:
... reader = csv.DictReader(csvfile, delimiter='\t')
... for row in reader:
... # append your lists
... print(row['ID'], row['Gender'])
答案 0 :(得分：44)
我写了日期扩展来获取特定工作日的日期，这里使用Swift 4是多么容易，
Date.today().next(.monday) // Feb 12, 2018 at 12:00 AM
Date.today().next(.sunday) // Feb 11, 2018 at 12:00 AM
Date.today().previous(.sunday) // Feb 4, 2018 at 12:00 AM
Date.today().previous(.monday) // Feb 5, 2018 at 12:00 AM
Date.today().previous(.thursday) // Feb 1, 2018 at 12:00 AM
Date.today().next(.thursday) // Feb 15, 2018 at 12:00 AM
Date.today().previous(.thursday,
considerToday: true) // Feb 8, 2018 at 11:04 PM
Date.today().next(.monday)
.next(.sunday)
.next(.thursday) // Feb 22, 2018 at 12:00 AM
这是日期扩展名，
extension Date {
static func today() -> Date {
return Date()
}
func next(_ weekday: Weekday, considerToday: Bool = false) -> Date {
return get(.Next,
weekday,
considerToday: considerToday)
}
func previous(_ weekday: Weekday, considerToday: Bool = false) -> Date {
return get(.Previous,
weekday,
considerToday: considerToday)
}
func get(_ direction: SearchDirection,
_ weekDay: Weekday,
considerToday consider: Bool = false) -> Date {
let dayName = weekDay.rawValue
let weekdaysName = getWeekDaysInEnglish().map { $0.lowercased() }
assert(weekdaysName.contains(dayName), "weekday symbol should be in form \(weekdaysName)")
let searchWeekdayIndex = weekdaysName.index(of: dayName)! + 1
let calendar = Calendar(identifier: .gregorian)
if consider && calendar.component(.weekday, from: self) == searchWeekdayIndex {
return self
}
var nextDateComponent = DateComponents()
nextDateComponent.weekday = searchWeekdayIndex
let date = calendar.nextDate(after: self,
matching: nextDateComponent,
matchingPolicy: .nextTime,
direction: direction.calendarSearchDirection)
return date!
}
}
// MARK: Helper methods
extension Date {
func getWeekDaysInEnglish() -> [String] {
var calendar = Calendar(identifier: .gregorian)
calendar.locale = Locale(identifier: "en_US_POSIX")
return calendar.weekdaySymbols
}
enum Weekday: String {
case monday, tuesday, wednesday, thursday, friday, saturday, sunday
}
enum SearchDirection {
case Next
case Previous
var calendarSearchDirection: Calendar.SearchDirection {
switch self {
case .Next:
return .forward
case .Previous:
return .backward
}
}
}
}
答案 1 :(得分：24)
您可以使用第一个工作日为星期一的日历ISO8601：
Swift 3或更高版本
var mondaysDate: Date {
return Calendar(identifier: .iso8601).date(from: Calendar(identifier: .iso8601).dateComponents([.yearForWeekOfYear, .weekOfYear], from: Date()))!
}
print(mondaysDate.description(with: .current)) // Monday, July 16, 2018 at 12:00:00 AM Brasilia Standard Time"
作为扩展名：
extension Calendar {
static let iso8601 = Calendar(identifier: .iso8601)
}
extension Date {
var currentWeekMonday: Date {
return Calendar.iso8601.date(from: Calendar.iso8601.dateComponents([.yearForWeekOfYear, .weekOfYear], from: self))!
}
}
let currentWeekMonday = Date().currentWeekMonday
print(currentWeekMonday.description(with: .current)) // Monday, July 16, 2018 at 12:00:00 AM Brasilia Standard Time
答案 2 :(得分：8)
这是我创建的扩展程序，首先它会找到星期日，然后再添加一天
if someExpression then onePossibility else otherPossibility答案 3 :(得分：6)
这是Sandeep's answer的简化版。
用法：
Date().next(.monday)
Date().next(.monday, considerToday: true)
Date().next(.monday, direction: .backward)
扩展：
public func next(_ weekday: Weekday,
direction: Calendar.SearchDirection = .forward,
considerToday: Bool = false) -> Date
{
let calendar = Calendar(identifier: .gregorian)
let components = DateComponents(weekday: weekday.rawValue)
if considerToday &&
calendar.component(.weekday, from: self) == weekday.rawValue
{
return self
}
return calendar.nextDate(after: self,
matching: components,
matchingPolicy: .nextTime,
direction: direction)!
}
public enum Weekday: Int {
case sunday = 1, monday, tuesday, wednesday, thursday, friday, saturday
}
答案 4 :(得分：3)
尝试使用：
calendar.firstWeekday = 2
修改
更具体地说：NSCalendar.currentCalendar()返回用户日历。根据文件：
返回的日历由当前用户所选系统区域设置的设置构成，并覆盖用户在“系统偏好设置”中指定的任何自定义设置。
如果您希望星期一作为第一天，我认为您应该使用：
let calendar = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian)!
calendar!.firstWeekday = 2
答案 5 :(得分：0)
加入@Saneep回答
如果您希望根据给定/当前日期获得确切的日期时间（假设您想要将星期一＆dates. {date} - ＆gt; 23-05-2016 12:00:00转换为23-05-2016 05:35:17），请尝试以下操作：< / p>
func convertDate(date: NSDate, toGivendate: NSDate) -> NSDate {
let calendar = NSCalendar.currentCalendar()
let comp = calendar.components([.Year, .Month, .Day, .Hour, .Minute, .Second], fromDate: toGivendate)
let hour = comp.hour
let minute = comp.minute
let second = comp.second
let dateComp = calendar.components([.Year, .Month, .Day], fromDate: date)
let year = dateComp.year
let month = dateComp.month
let day = dateComp.day
let components = NSDateComponents()
components.year = year
components.month = month
components.day = day
components.hour = hour
components.minute = minute
components.second = second
let newConvertedDate = calendar.dateFromComponents(components)
return newConvertedDate!
}
答案 6 :(得分：0)
Swift 4解决方案
我已经根据自己的要求弄清楚了，在那里我找到了后续的日期。
1. Today
2. Tomorrow
3. This Week
4. This Weekend
5. Next Week
6. Next Weekend
因此，我创建了Date Extension来获取当前周和下周的日期。
代码
extension Date {
func getWeekDates() -> (thisWeek:[Date],nextWeek:[Date]) {
var tuple: (thisWeek:[Date],nextWeek:[Date])
var arrThisWeek: [Date] = []
for i in 0..<7 {
arrThisWeek.append(Calendar.current.date(byAdding: .day, value: i, to: startOfWeek)!)
}
var arrNextWeek: [Date] = []
for i in 1...7 {
arrNextWeek.append(Calendar.current.date(byAdding: .day, value: i, to: arrThisWeek.last!)!)
}
tuple = (thisWeek: arrThisWeek,nextWeek: arrNextWeek)
return tuple
}
var tomorrow: Date {
return Calendar.current.date(byAdding: .day, value: 1, to: noon)!
}
var noon: Date {
return Calendar.current.date(bySettingHour: 12, minute: 0, second: 0, of: self)!
}
var startOfWeek: Date {
let gregorian = Calendar(identifier: .gregorian)
let sunday = gregorian.date(from: gregorian.dateComponents([.yearForWeekOfYear, .weekOfYear], from: self))
return gregorian.date(byAdding: .day, value: 1, to: sunday!)!
}
func toDate(format: String) -> String {
let formatter = DateFormatter()
formatter.dateFormat = format
return formatter.string(from: self)
}
}
用法：
let arrWeekDates = Date().getWeekDates() // Get dates of Current and Next week.
let dateFormat = "MMM dd" // Date format
let thisMon = arrWeekDates.thisWeek.first!.toDate(format: dateFormat)
let thisSat = arrWeekDates.thisWeek[arrWeekDates.thisWeek.count - 2].toDate(format: dateFormat)
let thisSun = arrWeekDates.thisWeek[arrWeekDates.thisWeek.count - 1].toDate(format: dateFormat)
let nextMon = arrWeekDates.nextWeek.first!.toDate(format: dateFormat)
let nextSat = arrWeekDates.nextWeek[arrWeekDates.nextWeek.count - 2].toDate(format: dateFormat)
let nextSun = arrWeekDates.nextWeek[arrWeekDates.nextWeek.count - 1].toDate(format: dateFormat)
print("Today: \(Date().toDate(format: dateFormat))") // Sep 26
print("Tomorrow: \(Date().tomorrow.toDate(format: dateFormat))") // Sep 27
print("This Week: \(thisMon) - \(thisSun)") // Sep 24 - Sep 30
print("This Weekend: \(thisSat) - \(thisSun)") // Sep 29 - Sep 30
print("Next Week: \(nextMon) - \(nextSun)") // Oct 01 - Oct 07
print("Next Weekend: \(nextSat) - \(nextSun)") // Oct 06 - Oct 07
您可以根据需要修改Extension。
谢谢！
答案 7 :(得分：0)
简单代码（请记住要更好地处理可选内容）：
let now = Date()
var calendar = Calendar(identifier: .gregorian)
let timeZone = TimeZone(identifier: "UTC")!
let desiredWeekDay = 2
let weekDay = calendar.component(.weekday, from: now)
var weekDayDate = calendar.date(bySetting: .weekday, value: desiredWeekDay, of: now)!
/// Swift will give back the closest day matching the value above so we need to manipulate it to be always included at cuurent week.
if weekDayDate > now, weekDay > desiredWeekDay {
weekDayDate = weekDayDate - 7*24*60*60
}
print(weekDayDate)