本文整理汇总了Python中blaze.expr.TableSymbol.head方法的典型用法代码示例。如果您正苦于以下问题：Python TableSymbol.head方法的具体用法？Python TableSymbol.head怎么用？Python TableSymbol.head使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类blaze.expr.TableSymbol的用法示例。
在下文中一共展示了TableSymbol.head方法的4个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: test_length
# 需要导入模块: from blaze.expr import TableSymbol [as 别名]
# 或者: from blaze.expr.TableSymbol import head [as 别名]
def test_length():
t = TableSymbol('t', '10 * {name: string, amount: int}')
assert t.dshape == dshape('10 * {name: string, amount: int}')
assert len(t) == 10
assert len(t.name) == 10
assert len(t[['name']]) == 10
assert len(t.sort('name')) == 10
assert len(t.head(5)) == 5
assert len(t.head(50)) == 10示例2: test_length
# 需要导入模块: from blaze.expr import TableSymbol [as 别名]
# 或者: from blaze.expr.TableSymbol import head [as 别名]
def test_length():
t = TableSymbol('t', '10 * {name: string, amount: int}')
s = TableSymbol('s', '{name:string, amount:int}')
assert t.dshape == dshape('10 * {name: string, amount: int}')
assert len(t) == 10
assert len(t.name) == 10
assert len(t[['name']]) == 10
assert len(t.sort('name')) == 10
assert len(t.head(5)) == 5
assert len(t.head(50)) == 10
with pytest.raises(ValueError):
len(s)示例3: test_head
# 需要导入模块: from blaze.expr import TableSymbol [as 别名]
# 或者: from blaze.expr.TableSymbol import head [as 别名]
def test_head():
t = TableSymbol('t', '{name: string, amount: int32, id: int32}')
s = t.head(10)
assert eval(str(s)).isidentical(s)
assert s.schema == t.schema示例4: sin
# 需要导入模块: from blaze.expr import TableSymbol [as 别名]
# 或者: from blaze.expr.TableSymbol import head [as 别名]
# {expr: [list-of-exclusions]}
expressions = {
t: [],
t['id']: [],
t.id.max(): [],
t.amount.sum(): [],
t.amount + 1: [mongo],
sin(t.amount): [sql, mongo], # sqlite doesn't support trig
exp(t.amount): [sql, mongo],
t.amount > 50: [mongo],
t[t.amount > 50]: [],
t.like(name='Alic*'): [],
t.sort('name'): [bc],
t.sort('name', ascending=False): [bc],
t.head(3): [],
t.name.distinct(): [],
t[t.amount > 50]['name']: [], # odd ordering issue
t.id.map(lambda x: x + 1, '{id: int}'): [sql, mongo],
t[t.amount > 50]['name']: [],
by(t.name, t.amount.sum()): [],
by(t.id, t.id.count()): [],
by(t[['id', 'amount']], t.id.count()): [],
by(t[['id', 'amount']], (t.amount + 1).sum()): [mongo],
by(t[['id', 'amount']], t.name.nunique()): [mongo],
by(t.id, t.amount.count()): [],
by(t.id, t.id.nunique()): [mongo],
# by(t, t.count()): [],
# by(t.id, t.count()): [df],
t[['amount', 'id']]: [x], # https://github.com/numpy/numpy/issues/3256
t[['id', 'amount']]: [x, bc], # bcolz sorting