Skip to content

pydsa.digits

to_digits 

to_digits(
    num: Union[int, str],
    reverse: bool = False,
    base: int = 10,
) -> List[int]

The digits of num in the given base as ints, most significant first.

With reverse=True the least significant digit comes first, so digit i is the coefficient of base**i. A negative int loses its sign. A str is read one character at a time, so leading zeros are kept; base=2 gives the bits.

Source code in pydsa/digits.py 
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
def to_digits(num: Union[int, str], reverse: bool = False, base: int = 10) -> List[int]:
    """The digits of num in the given base as ints, most significant first.

    With reverse=True the least significant digit comes first, so digit i
    is the coefficient of base**i. A negative int loses its sign. A str is
    read one character at a time, so leading zeros are kept; base=2 gives
    the bits.
    """
    if isinstance(num, str):
        ds = [int(c, base) for c in num.lstrip("-")]
    else:
        num = abs(num)
        ds = []
        while True:
            num, d = divmod(num, base)
            ds.append(d)
            if num == 0:
                break
        ds.reverse()
    return ds[::-1] if reverse else ds

to_int 

to_int(
    digits: List[int], reverse: bool = False, base: int = 10
) -> int

The int whose digits in the given base are the list, most significant first.

With reverse=True the list is read least significant first, the inverse of to_digits(num, reverse=True). An empty list is 0. base=2 reads bits.

Source code in pydsa/digits.py 
30
31
32
33
34
35
36
37
38
39
40
def to_int(digits: List[int], reverse: bool = False, base: int = 10) -> int:
    """The int whose digits in the given base are the list, most significant first.

    With reverse=True the list is read least significant first, the inverse
    of to_digits(num, reverse=True). An empty list is 0. base=2 reads bits.
    """
    ds = digits[::-1] if reverse else digits
    out = 0
    for d in ds:
        out = out * base + d
    return out

even 

even(n: int) -> bool

True when n is even.

Source code in pydsa/digits.py 
43
44
45
def even(n: int) -> bool:
    """True when n is even."""
    return n % 2 == 0

odd 

odd(n: int) -> bool

True when n is odd.

Source code in pydsa/digits.py 
48
49
50
def odd(n: int) -> bool:
    """True when n is odd."""
    return n % 2 == 1