segpy.header module¶

class segpy.header.BaseHeader(*args, **kwargs)¶

Bases: object

An abstract base class for header format definitions.

Prefer to inherit from Header rather than BaseHeader.

copy(**updates)¶

classmethod ordered_field_names()¶

The ordered list of field names.

This is a metamethod which should be called on cls.

Returns:	An tuple containing the field names in order.

class segpy.header.FormatMeta¶

Bases: type

A metaclass for header format classes.

class segpy.header.Header(*args, **kwargs)¶

Bases: segpy.header.BaseHeader

A base class for header definition classes.

class segpy.header.HeaderFieldDescriptor(value_type, offset, default, documentation)¶: Bases: object

class segpy.header.NamedField(value_type, offset, default, documentation)¶

Bases: object

Instances of NamedField can be detected by the NamedDescriptorResolver metaclass.

default¶: The default value of the field. Must be convertible to value_type.

documentation¶: A descriptive text string.

name¶: The field name.

offset¶: The offset in bytes from the beginning of the header.

value_type¶: The field value type (e.g. Int32)

class segpy.header.SubFormatMeta(mcs, name, bases, namespace, parent_format, parent_field_names)¶

Bases: segpy.header.FormatMeta

A metaclass for a format class which has a subset of the fields in an existing format class.

SubFormat classes can be used to reduce storage requirements and increase performance, since they can be used to generate simpler HeaderPackers.

Usage:

class MySubFormat(metaclass=SubFormatMeta,
                  parent_format=MyFormatClass,
                  parent_field_names=[
                     'first_field_name',
                     'second_field_name']):
    pass

segpy.header.are_equal(header_a, header_b)¶: Compare two headers for equality.

Note

This is not implemented as __eq__() to prevent recursive behaviour in the header descriptor.

segpy.header.field(value_type, offset, default, documentation)¶

offset: The offset in bytes for this field from the start of the header.

default: The default value for this field.

documentation: A docstring for the field. The first sentence should be usable

as a brief description.

Returns:	An instance of a subclass of HeaderFieldDescriptor class.

segpy.header.is_public_non_field_attr(name, attr)¶