Module fpdf.util

Various utilities that could not be gathered logically in a specific module.

The contents of this module are internal to fpdf2, and not part of the public API. They may change at any time without prior warning or any deprecation period, in non-backward-compatible ways.

Functions

def buffer_subst(buffer, placeholder, value)

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def buffer_subst(buffer, placeholder, value):
    buffer_size = len(buffer)
    assert len(placeholder) == len(value), f"placeholder={placeholder} value={value}"
    buffer = buffer.replace(placeholder.encode(), value.encode(), 1)
    assert len(buffer) == buffer_size
    return buffer

def convert_unit(to_convert: float | int | Iterable[float | int | Iterable],
old_unit: str | numbers.Number,
new_unit: str | numbers.Number) ‑> float | tuple

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def convert_unit(
    to_convert: Union[float, int, Iterable[Union[float, int, Iterable]]],
    old_unit: Union[str, Number],
    new_unit: Union[str, Number],
) -> Union[float, tuple]:
    """
     Convert a number or sequence of numbers from one unit to another.

     If either unit is a number it will be treated as the number of points per unit.  So 72 would mean 1 inch.

     Args:
        to_convert (float, int, Iterable): The number / list of numbers, or points, to convert
        old_unit (str, float, int): A unit accepted by fpdf.FPDF or a number
        new_unit (str, float, int): A unit accepted by fpdf.FPDF or a number
    Returns:
        (float, tuple): to_convert converted from old_unit to new_unit or a tuple of the same
    """
    unit_conversion_factor = get_scale_factor(new_unit) / get_scale_factor(old_unit)
    if isinstance(to_convert, Iterable):
        return tuple(convert_unit(i, 1, unit_conversion_factor) for i in to_convert)
    return to_convert / unit_conversion_factor

Convert a number or sequence of numbers from one unit to another.

If either unit is a number it will be treated as the number of points per unit. So 72 would mean 1 inch.

Args: to_convert (float, int, Iterable): The number / list of numbers, or points, to convert old_unit (str, float, int): A unit accepted by fpdf.FPDF or a number new_unit (str, float, int): A unit accepted by fpdf.FPDF or a number

Returns

(float, tuple): to_convert converted from old_unit to new_unit or a tuple of the same

def escape_parens(s)

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def escape_parens(s):
    """Add a backslash character before , ( and )"""
    if isinstance(s, str):
        return (
            s.replace("\\", "\\\\")
            .replace(")", "\\)")
            .replace("(", "\\(")
            .replace("\r", "\\r")
        )
    return (
        s.replace(b"\\", b"\\\\")
        .replace(b")", b"\\)")
        .replace(b"(", b"\\(")
        .replace(b"\r", b"\\r")
    )

Add a backslash character before , ( and )

def get_gc_managed_objs_total_size() ‑> str

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def get_gc_managed_objs_total_size() -> str:
    "From experiments, not very reliable"
    try:
        # pylint: disable=import-outside-toplevel
        from pympler.muppy import get_objects, getsizeof

        objs_total_size = sum(getsizeof(obj) for obj in get_objects())
        return f"{objs_total_size / 1024 / 1024:.1f} MiB"
    except ImportError:
        warnings.warn("pympler could not be imported - Run: pip install pympler")
        return "<unavailable>"

From experiments, not very reliable

def get_mem_usage(prefix) ‑> str

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def get_mem_usage(prefix) -> str:
    _collected_count = gc.collect()
    rss = get_process_rss()
    # heap_size, stack_size = get_process_heap_and_stack_sizes()
    # objs_size_sum = get_gc_managed_objs_total_size()
    pillow = get_pillow_allocated_memory()
    # malloc_stats = "Malloc stats: " + get_pymalloc_allocated_over_total_size()
    malloc_stats = ""
    if is_tracing():
        malloc_stats = "Malloc stats: " + get_tracemalloc_traced_memory()
    return f"{prefix:<40} {malloc_stats} | Pillow: {pillow} | Process RSS: {rss}"

def get_pillow_allocated_memory() ‑> str

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def get_pillow_allocated_memory() -> str:
    # pylint: disable=c-extension-no-member,import-outside-toplevel
    from PIL import Image

    stats = Image.core.get_stats()
    blocks_in_use = stats["allocated_blocks"] - stats["freed_blocks"]
    return f"{blocks_in_use * PIL_MEM_BLOCK_SIZE_IN_MIB:.1f} MiB"

def get_process_heap_and_stack_sizes() ‑> Tuple[str]

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def get_process_heap_and_stack_sizes() -> Tuple[str]:
    heap_size_in_mib, stack_size_in_mib = "<unavailable>", "<unavailable>"
    pid = os.getpid()
    try:
        with open(f"/proc/{pid}/maps", encoding="utf8") as maps_file:
            maps_lines = list(maps_file)
    except FileNotFoundError:  # This file only exists under Linux
        return heap_size_in_mib, stack_size_in_mib
    for line in maps_lines:
        words = line.split()
        addr_range, path = words[0], words[-1]
        addr_start, addr_end = addr_range.split("-")
        addr_start, addr_end = int(addr_start, 16), int(addr_end, 16)
        size = addr_end - addr_start
        if path == "[heap]":
            heap_size_in_mib = f"{size / 1024 / 1024:.1f} MiB"
        elif path == "[stack]":
            stack_size_in_mib = f"{size / 1024 / 1024:.1f} MiB"
    return heap_size_in_mib, stack_size_in_mib

def get_process_rss() ‑> str

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def get_process_rss() -> str:
    rss_as_mib = get_process_rss_as_mib()
    if rss_as_mib:
        return f"{rss_as_mib:.1f} MiB"
    return "<unavailable>"

def get_process_rss_as_mib() ‑> numbers.Number | None

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def get_process_rss_as_mib() -> Union[Number, None]:
    "Inspired by psutil source code"
    pid = os.getpid()
    try:
        with open(f"/proc/{pid}/statm", encoding="utf8") as statm:
            return (
                int(statm.readline().split()[1])
                * os.sysconf("SC_PAGE_SIZE")
                / 1024
                / 1024
            )
    except FileNotFoundError:  # /proc files only exist under Linux
        return None

Inspired by psutil source code

def get_pymalloc_allocated_over_total_size() ‑> Tuple[str]

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def get_pymalloc_allocated_over_total_size() -> Tuple[str]:
    """
    Get PyMalloc stats from sys._debugmallocstats()
    From experiments, not very reliable
    """
    try:
        # pylint: disable=import-outside-toplevel
        from pymemtrace.debug_malloc_stats import get_debugmallocstats

        allocated, total = -1, -1
        for line in get_debugmallocstats().decode().splitlines():
            if line.startswith("Total"):
                total = int(line.split()[-1].replace(",", ""))
            elif line.startswith("# bytes in allocated blocks"):
                allocated = int(line.split()[-1].replace(",", ""))
        return f"{allocated / 1024 / 1024:.1f} / {total / 1024 / 1024:.1f} MiB"
    except ImportError:
        warnings.warn("pymemtrace could not be imported - Run: pip install pymemtrace")
        return "<unavailable>"

Get PyMalloc stats from sys._debugmallocstats() From experiments, not very reliable

def get_scale_factor(unit: str | numbers.Number) ‑> float

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def get_scale_factor(unit: Union[str, Number]) -> float:
    """
    Get how many pts are in a unit. (k)

    Args:
        unit (str, float, int): Any of "pt", "mm", "cm", "in", or a number.
    Returns:
        float: The number of points in that unit (assuming 72dpi)
    Raises:
        ValueError
    """
    if isinstance(unit, Number):
        return float(unit)

    if unit == "pt":
        return 1
    if unit == "mm":
        return 72 / 25.4
    if unit == "cm":
        return 72 / 2.54
    if unit == "in":
        return 72.0
    raise ValueError(f"Incorrect unit: {unit}")

Get how many pts are in a unit. (k)

Args

unit : str, float, int

Any of "pt", "mm", "cm", "in", or a number.

Returns

float

The number of points in that unit (assuming 72dpi)

Raises

ValueError

def get_tracemalloc_traced_memory() ‑> str

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def get_tracemalloc_traced_memory() -> str:
    "Requires python -X tracemalloc"
    current, peak = get_traced_memory()
    return f"{current / 1024 / 1024:.1f} (peak={peak / 1024 / 1024:.1f}) MiB"

Requires python -X tracemalloc

def int2roman(n)

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def int2roman(n):
    "Convert an integer to Roman numeral"
    result = ""
    for numeral, integer in ROMAN_NUMERAL_MAP:
        while n >= integer:
            result += numeral
            n -= integer
    return result

Convert an integer to Roman numeral

def int_to_letters(n: int) ‑> str

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def int_to_letters(n: int) -> str:
    "Convert an integer to a letter value (A to Z for the first 26, then AA to ZZ, and so on)"
    if n > 25:
        return int_to_letters(int((n / 26) - 1)) + int_to_letters(n % 26)
    return chr(n + ord("A"))

Convert an integer to a letter value (A to Z for the first 26, then AA to ZZ, and so on)

def print_mem_usage(prefix)

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def print_mem_usage(prefix):
    print(get_mem_usage(prefix))

Classes

class Padding (top: numbers.Number = 0,
right: numbers.Number = 0,
bottom: numbers.Number = 0,
left: numbers.Number = 0)

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class Padding(NamedTuple):
    top: Number = 0
    right: Number = 0
    bottom: Number = 0
    left: Number = 0

    @classmethod
    def new(cls, padding: Union[int, float, tuple, list]):
        """Return a 4-tuple of padding values from a single value or a 2, 3 or 4-tuple according to CSS rules"""
        if isinstance(padding, (int, float)):
            return Padding(padding, padding, padding, padding)
        if len(padding) == 2:
            return Padding(padding[0], padding[1], padding[0], padding[1])
        if len(padding) == 3:
            return Padding(padding[0], padding[1], padding[2], padding[1])
        if len(padding) == 4:
            return Padding(*padding)

        raise ValueError(
            f"padding shall be a number or a sequence of 2, 3 or 4 numbers, got {str(padding)}"
        )

Padding(top, right, bottom, left)

Ancestors

• builtins.tuple

Static methods

def new(padding: int | float | tuple | list)

Return a 4-tuple of padding values from a single value or a 2, 3 or 4-tuple according to CSS rules

Instance variables

var bottom : numbers.Number

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class Padding(NamedTuple):
    top: Number = 0
    right: Number = 0
    bottom: Number = 0
    left: Number = 0

    @classmethod
    def new(cls, padding: Union[int, float, tuple, list]):
        """Return a 4-tuple of padding values from a single value or a 2, 3 or 4-tuple according to CSS rules"""
        if isinstance(padding, (int, float)):
            return Padding(padding, padding, padding, padding)
        if len(padding) == 2:
            return Padding(padding[0], padding[1], padding[0], padding[1])
        if len(padding) == 3:
            return Padding(padding[0], padding[1], padding[2], padding[1])
        if len(padding) == 4:
            return Padding(*padding)

        raise ValueError(
            f"padding shall be a number or a sequence of 2, 3 or 4 numbers, got {str(padding)}"
        )

Alias for field number 2

var left : numbers.Number

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class Padding(NamedTuple):
    top: Number = 0
    right: Number = 0
    bottom: Number = 0
    left: Number = 0

    @classmethod
    def new(cls, padding: Union[int, float, tuple, list]):
        """Return a 4-tuple of padding values from a single value or a 2, 3 or 4-tuple according to CSS rules"""
        if isinstance(padding, (int, float)):
            return Padding(padding, padding, padding, padding)
        if len(padding) == 2:
            return Padding(padding[0], padding[1], padding[0], padding[1])
        if len(padding) == 3:
            return Padding(padding[0], padding[1], padding[2], padding[1])
        if len(padding) == 4:
            return Padding(*padding)

        raise ValueError(
            f"padding shall be a number or a sequence of 2, 3 or 4 numbers, got {str(padding)}"
        )

Alias for field number 3

var right : numbers.Number

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class Padding(NamedTuple):
    top: Number = 0
    right: Number = 0
    bottom: Number = 0
    left: Number = 0

    @classmethod
    def new(cls, padding: Union[int, float, tuple, list]):
        """Return a 4-tuple of padding values from a single value or a 2, 3 or 4-tuple according to CSS rules"""
        if isinstance(padding, (int, float)):
            return Padding(padding, padding, padding, padding)
        if len(padding) == 2:
            return Padding(padding[0], padding[1], padding[0], padding[1])
        if len(padding) == 3:
            return Padding(padding[0], padding[1], padding[2], padding[1])
        if len(padding) == 4:
            return Padding(*padding)

        raise ValueError(
            f"padding shall be a number or a sequence of 2, 3 or 4 numbers, got {str(padding)}"
        )

Alias for field number 1

var top : numbers.Number

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class Padding(NamedTuple):
    top: Number = 0
    right: Number = 0
    bottom: Number = 0
    left: Number = 0

    @classmethod
    def new(cls, padding: Union[int, float, tuple, list]):
        """Return a 4-tuple of padding values from a single value or a 2, 3 or 4-tuple according to CSS rules"""
        if isinstance(padding, (int, float)):
            return Padding(padding, padding, padding, padding)
        if len(padding) == 2:
            return Padding(padding[0], padding[1], padding[0], padding[1])
        if len(padding) == 3:
            return Padding(padding[0], padding[1], padding[2], padding[1])
        if len(padding) == 4:
            return Padding(*padding)

        raise ValueError(
            f"padding shall be a number or a sequence of 2, 3 or 4 numbers, got {str(padding)}"
        )

Alias for field number 0