def test_simple_methods():
df = DaskDataFrame([], "a:str,b:int")
assert df.empty
assert 0 == df.count()
assert not df.is_local
df = DaskDataFrame([["a", 1], ["b", "2"]], "x:str,y:double")
assert not df.empty
assert 2 == df.count()
assert ["a", 1.0] == df.peek_array()
assert dict(x="a", y=1.0) == df.peek_dict()
df_eq(
PandasDataFrame(df.as_pandas()),
[["a", 1.0], ["b", 2.0]],
"x:str,y:double",
throw=True,
)
def test_init():
df = DaskDataFrame(schema="a:str,b:int")
assert df.is_bounded
assert df.count() == 0
assert df.schema == "a:str,b:int"
pdf = pandas.DataFrame([["a", 1], ["b", 2]])
raises(FugueDataFrameInitError, lambda: DaskDataFrame(pdf))
df = DaskDataFrame(pdf, "a:str,b:str")
assert [["a", "1"], ["b", "2"]] == df.as_pandas().values.tolist()
df = DaskDataFrame(pdf, "a:str,b:int")
assert [["a", 1], ["b", 2]] == df.as_pandas().values.tolist()
df = DaskDataFrame(pdf, "a:str,b:double")
assert [["a", 1.0], ["b", 2.0]] == df.as_pandas().values.tolist()
pdf = DaskDataFrame([["a", 1], ["b", 2]], "a:str,b:int").native["b"]
assert isinstance(pdf, pd.Series)
df = DaskDataFrame(pdf, "b:str")
assert [["1"], ["2"]] == df.as_pandas().values.tolist()
df = DaskDataFrame(pdf, "b:double")
assert [[1.0], [2.0]] == df.as_pandas().values.tolist()
pdf = DaskDataFrame([["a", 1], ["b", 2]], "x:str,y:long").native
df = DaskDataFrame(pdf)
assert df.schema == "x:str,y:long"
df = DaskDataFrame(pdf, "y:str,x:str")
assert [["1", "a"], ["2", "b"]] == df.as_pandas().values.tolist()
ddf = DaskDataFrame(df)
assert [["1", "a"], ["2", "b"]] == ddf.as_pandas().values.tolist()
assert df.native is ddf.native # no real copy happened
df = DaskDataFrame([["a", 1], ["b", "2"]], "x:str,y:double")
assert [["a", 1.0], ["b", 2.0]] == df.as_pandas().values.tolist()
df = DaskDataFrame([], "x:str,y:double")
assert [] == df.as_pandas().values.tolist()
raises(FugueDataFrameInitError, lambda: DaskDataFrame(123))