Go中的错误解析时间，具有可变的微秒数

Question

I'm trying to parse a string into a time object. The issue is that the number of digits in the microseconds term changes, which breaks the parsing. For example, this works fine:

package main

import (
    "fmt"
    "time"
)

func main() {
    timeText := "2017-03-25T10:01:02.1234567Z"
    layout := "2006-01-02T15:04:05.0000000Z"
    t, _ := time.Parse(layout, timeText)
    fmt.Println(t)
}

But this causes an error, because the number of microseconds digits doesn't match the layout:

package main

import (
    "fmt"
    "time"
)

func main() {
    timeText := "2017-03-25T10:01:02.123Z" // notice only 3 microseconds digits here
    layout := "2006-01-02T15:04:05.0000000Z"
    t, _ := time.Parse(layout, timeText)
    fmt.Println(t)
}

How do I fix this so that the microseconds term is still parsed, but it doesn't matter how many digits there are?

Answer 1

Use 9s instead of zeros in the subsecond format, for example:

timeText := "2017-03-25T10:01:02.1234567Z"
layout := "2006-01-02T15:04:05.99Z"
t, _ := time.Parse(layout, timeText)
fmt.Println(t) //prints 2017-03-25 10:01:02.1234567 +0000 UTC

From the docs:

// Fractional seconds can be printed by adding a run of 0s or 9s after
// a decimal point in the seconds value in the layout string.
// If the layout digits are 0s, the fractional second is of the specified
// width. Note that the output has a trailing zero.
do("0s for fraction", "15:04:05.00000", "11:06:39.12340")

// If the fraction in the layout is 9s, trailing zeros are dropped.
do("9s for fraction", "15:04:05.99999999", "11:06:39.1234")