time — 时钟时间

Comparing Clocks

time_get_clock_info.py

import textwrap
import time

available_clocks = [
    ('clock', time.clock),
    ('monotonic', time.monotonic),
    ('perf_counter', time.perf_counter),
    ('process_time', time.process_time),
    ('time', time.time),
]

for clock_name, func in available_clocks:
    print(textwrap.dedent('''\
    {name}:
        adjustable    : {info.adjustable}
        implementation: {info.implementation}
        monotonic     : {info.monotonic}
        resolution    : {info.resolution}
        current       : {current}
    ''').format(
        name=clock_name,
        info=time.get_clock_info(clock_name),
        current=func())
    )

Wall Clock Time

time_time.py

import time

print('The time is:', time.time())

time_ctime.py

import time

print('The time is      :', time.ctime())
later = time.time() + 15
print('15 secs from now :', time.ctime(later))

Monotonic Clocks

time_monotonic.py

import time

start = time.monotonic()
time.sleep(0.1)
end = time.monotonic()
print('start : {:>9.2f}'.format(start))
print('end   : {:>9.2f}'.format(end))
print('span  : {:>9.2f}'.format(end - start))

time_clock.py

import hashlib
import time

# Data to use to calculate md5 checksums
data = open(__file__, 'rb').read()

for i in range(5):
    h = hashlib.sha1()
    print(time.ctime(), ': {:0.3f} {:0.3f}'.format(
        time.time(), time.clock()))
    for i in range(300000):
        h.update(data)
    cksum = h.digest()

time_clock_sleep.py

import time

template = '{} - {:0.2f} - {:0.2f}'

print(template.format(
    time.ctime(), time.time(), time.clock())
)

for i in range(3, 0, -1):
    print('Sleeping', i)
    time.sleep(i)
    print(template.format(
        time.ctime(), time.time(), time.clock())
    )

Performance Counter

time_perf_counter.py

import hashlib
import time

# Data to use to calculate md5 checksums
data = open(__file__, 'rb').read()

loop_start = time.perf_counter()

for i in range(5):
    iter_start = time.perf_counter()
    h = hashlib.sha1()
    for i in range(300000):
        h.update(data)
    cksum = h.digest()
    now = time.perf_counter()
    loop_elapsed = now - loop_start
    iter_elapsed = now - iter_start
    print(time.ctime(), ': {:0.3f} {:0.3f}'.format(
        iter_elapsed, loop_elapsed))

Time Components

time_struct.py

import time


def show_struct(s):
    print('  tm_year :', s.tm_year)
    print('  tm_mon  :', s.tm_mon)
    print('  tm_mday :', s.tm_mday)
    print('  tm_hour :', s.tm_hour)
    print('  tm_min  :', s.tm_min)
    print('  tm_sec  :', s.tm_sec)
    print('  tm_wday :', s.tm_wday)
    print('  tm_yday :', s.tm_yday)
    print('  tm_isdst:', s.tm_isdst)

print('gmtime:')
show_struct(time.gmtime())
print('\nlocaltime:')
show_struct(time.localtime())
print('\nmktime:', time.mktime(time.localtime()))

Working with Time Zones 使用时区

time_timezone.py

import time
import os


def show_zone_info():
    print('  TZ    :', os.environ.get('TZ', '(not set)'))
    print('  tzname:', time.tzname)
    print('  Zone  : {} ({})'.format(
        time.timezone, (time.timezone / 3600)))
    print('  DST   :', time.daylight)
    print('  Time  :', time.ctime())
    print()


print('Default :')
show_zone_info()

ZONES = [
    'GMT',
    'Europe/Amsterdam',
]

for zone in ZONES:
    os.environ['TZ'] = zone
    time.tzset()
    print(zone, ':')
    show_zone_info()

Parsing and Formatting Times 解析与格式化时间

time_strptime.py

import time


def show_struct(s):
    print('  tm_year :', s.tm_year)
    print('  tm_mon  :', s.tm_mon)
    print('  tm_mday :', s.tm_mday)
    print('  tm_hour :', s.tm_hour)
    print('  tm_min  :', s.tm_min)
    print('  tm_sec  :', s.tm_sec)
    print('  tm_wday :', s.tm_wday)
    print('  tm_yday :', s.tm_yday)
    print('  tm_isdst:', s.tm_isdst)


now = time.ctime(1483391847.433716)
print('Now:', now)

parsed = time.strptime(now)
print('\nParsed:')
show_struct(parsed)

print('\nFormatted:',
      time.strftime("%a %b %d %H:%M:%S %Y", parsed))