year = float(input('Year'))

time_periods = {
    "Holocene": (0,.008),
    "Pleistocene": (.008,1.8),
    "Pliocene": (1.8,5.3),
    "Miocene": (5.3,23.8),
    "Oligocene": (23.8,33.7),
    "Eocene": (33.7,55.5),
    "Paleocene": (55.5,65),
    "Cretaceous": (65,145),
    "Jurassic": (145,213),
    "Triassic": (213,248),
    "Permian": (248,286),
    "Pennsylvanian": (286,325),
    "Mississippian": (325,360),
    "Devonian": (360,410),
    "Silurian": (410,440),
    "Ordovician": (440,505),
    "Cambrian": (505,544)
}

for name,(begin,end) in time_periods.items():
    if begin <= year <= end:
        tail = '{} million years ago was the geologic period known as {} according to USGS,2001.'.format(year, name)
        print(tail)
        break

9befaa4726dad0278d7e11c31a88fbd525f0a0b2
<mask token>

<mask token>
for name, (begin, end) in time_periods.items():
    if begin <= year <= end:
        tail = (
            '{} million years ago was the geologic period known as {} according to USGS,2001.'
            .format(year, name))
        print(tail)
        break

year = float(input('Year'))
time_periods = {'Holocene': (0, 0.008), 'Pleistocene': (0.008, 1.8),
    'Pliocene': (1.8, 5.3), 'Miocene': (5.3, 23.8), 'Oligocene': (23.8, 
    33.7), 'Eocene': (33.7, 55.5), 'Paleocene': (55.5, 65), 'Cretaceous': (
    65, 145), 'Jurassic': (145, 213), 'Triassic': (213, 248), 'Permian': (
    248, 286), 'Pennsylvanian': (286, 325), 'Mississippian': (325, 360),
    'Devonian': (360, 410), 'Silurian': (410, 440), 'Ordovician': (440, 505
    ), 'Cambrian': (505, 544)}
for name, (begin, end) in time_periods.items():
    if begin <= year <= end:
        tail = (
            '{} million years ago was the geologic period known as {} according to USGS,2001.'
            .format(year, name))
        print(tail)
        break

year = float(input('Year'))

time_periods = {
    "Holocene": (0,.008),
    "Pleistocene": (.008,1.8),
    "Pliocene": (1.8,5.3),
    "Miocene": (5.3,23.8),
    "Oligocene": (23.8,33.7),
    "Eocene": (33.7,55.5),
    "Paleocene": (55.5,65),
    "Cretaceous": (65,145),
    "Jurassic": (145,213),
    "Triassic": (213,248),
    "Permian": (248,286),
    "Pennsylvanian": (286,325),
    "Mississippian": (325,360),
    "Devonian": (360,410),
    "Silurian": (410,440),
    "Ordovician": (440,505),
    "Cambrian": (505,544)
}

for name,(begin,end) in time_periods.items():
    if begin <= year <= end:
        tail = '{} million years ago was the geologic period known as {} according to USGS,2001.'.format(year, name)
        print(tail)
        break
