bites 252

Author: [email protected]

.gitignore

@@ -33,3 +33,4 @@
 /16/README.md
 /246/README.md
 /251/README.md
+/252/README.md

252/series.py

@@ -0,0 +1,73 @@
+import numpy as np
+import pandas as pd
+
+
+def return_at_index(ser: pd.Series, idx: int) -> object:
+    """Return the Object at the given index of the Series
+    If you want to be extra careful catch and raise an error if
+       the index does not exist.
+    """
+    try:
+        return ser.get(idx)
+    except KeyError:
+        raise KeyError
+
+
+def get_slice(ser: pd.Series, start: int, end: int) -> pd.core.series.Series:
+    """Return the slice of the given Series in the range between
+    start and end.
+    """
+    return ser[start:end]
+
+
+def get_slice_inclusive(ser: pd.Series,
+                        start: int, end: int) -> pd.core.series.Series:
+    """Return the slice of the given Series in the range between
+    start and end inclusive.
+    """
+    return ser.loc[start:end]
+
+
+def return_head(ser: pd.Series, num: int) -> pd.core.series.Series:
+    """Return the first num elements of the given Series.
+    """
+    return ser.head(num)
+
+
+def return_tail(ser: pd.Series, num: int) -> pd.core.series.Series:
+    """Return the last num elements of the given Series.
+    """
+    return ser.tail(num)
+
+
+def get_index(ser: pd.Series) -> pd.core.indexes.base.Index:
+    """Return all indexes of the given Series.
+    """
+    return ser.index
+
+
+def get_values(ser: pd.Series) -> np.ndarray:
+    """Return all the values of the given Series.
+    """
+    return ser.values
+
+
+def get_every_second_indexes(ser: pd.Series,
+                             even_index=True) -> pd.core.series.Series:
+    """Return all rows where the index is either even or odd.
+    If even_index is True return every index where idx % 2 == 0
+    If even_index is False return every index where idx % 2 != 0
+    Assume default indexing i.e. 0 -> n
+    """
+    data = []
+    if even_index:
+        for key, val in ser.items():
+            if key % 2 == 0:
+                data.append(val)
+        newser = pd.Series(data=data, index=[x for x in range(len(data)*2) if x % 2 == 0])
+    else:
+        for key, val in ser.items():
+            if key % 2 != 0:
+                data.append(val)
+        newser = pd.Series(data=data, index=[x for x in range(len(data)*2) if x % 2 != 0])
+    return newser

252/test_series.py

@@ -0,0 +1,91 @@
+import inspect
+import string
+
+import pytest
+import numpy as np
+import pandas as pd
+
+import series as se
+
+
+@pytest.fixture()
+def float_series():
+    """Returns a pandas Series containing floats"""
+    return pd.Series([float(n) / 1000 for n in range(0, 1001)])
+
+
+@pytest.fixture()
+def alpha_series():
+    """Returns a pandas Series containing floats"""
+    dictionary = dict(zip(string.ascii_lowercase, range(1, 27)))
+    return pd.Series(dictionary)
+
+
+@pytest.mark.parametrize("arg, expected", [
+    (0, 0.000), (500, 0.500), (1000, 1.000)
+])
+def test_return_at_index(float_series, arg, expected):
+    assert se.return_at_index(float_series, arg) == expected
+
+
+def test_return_at_index_raise_exception(float_series):
+    with pytest.raises(KeyError):
+        float_series[1111]
+
+
+def test_get_slice(float_series):
+    slce = se.get_slice(float_series, 20, 25)
+    assert isinstance(slce, pd.core.series.Series)
+    assert len(slce) == 5
+    assert slce[24] == 0.024
+
+
+def test_get_slice_inclusive(float_series):
+    slce = se.get_slice_inclusive(float_series, 20, 25)
+    assert isinstance(slce, pd.core.series.Series)
+    assert len(slce) == 6
+    assert slce[25] == 0.025
+
+
+@pytest.mark.parametrize("arg, expected", [
+    (0, 0.000), (5, 0.005), (9, 0.009)
+])
+def test_return_head(float_series, arg, expected):
+    assert se.return_head(float_series, 10)[arg] == expected
+    assert ".head" in inspect.getsource(se.return_head)
+
+
+@pytest.mark.parametrize("arg, expected", [
+    (991, 0.991), (995, 0.995), (1000, 1.000)
+])
+def test_return_tail(float_series, arg, expected):
+    assert se.return_tail(float_series, 10)[arg] == expected
+    assert ".tail" in inspect.getsource(se.return_tail)
+
+
+def test_get_index(alpha_series):
+    idx = se.get_index(alpha_series)
+    assert isinstance(idx, pd.core.indexes.base.Index)
+    assert len(idx) == 26
+    assert all(c in string.ascii_lowercase for c in idx.values)
+    assert ".index" in inspect.getsource(se.get_index)
+
+
+def test_get_values(alpha_series):
+    vals = se.get_values(alpha_series)
+    assert isinstance(vals, np.ndarray)
+    assert len(vals) == 26
+    assert all(c in range(1, 27) for c in vals)
+
+
+def test_all_even_indexes_returned(float_series):
+    ser = se.get_every_second_indexes(float_series, True)
+    assert all(n % 2 == 0 for n in ser.index)
+    assert round(sum(ser), 1) == 250.5
+
+
+def test_all_odd_indexes_returned(float_series):
+    ser = se.get_every_second_indexes(float_series, False)
+    assert all(n % 2 == 1 for n in ser.index)
+    assert round(sum(ser), 1) == 250.0
+