API documentation

pyexiv2

pyexiv2.version_info = (0, 3, 2)

A tuple containing the three components of the version number: major, minor, micro.

pyexiv2.__version__ = '0.3.2'

The version of the module as a string (major.minor.micro).

pyexiv2.exiv2_version_info = (0, 25, 0)

A tuple containing the three components of the version number of libexiv2: major, minor, micro.

pyexiv2.__exiv2_version__ = '0.25.0'

The version of libexiv2 as a string (major.minor.micro).

pyexiv2.metadata

class pyexiv2.metadata.ImageMetadata(filename)

A container for all the metadata embedded in an image.

It provides convenient methods for the manipulation of EXIF, IPTC and XMP metadata embedded in image files such as JPEG and TIFF files, using Python types. It also provides access to the previews embedded in an image.

__delitem__(key)

Delete a metadata tag for a given key.

Parameters:key (string) – metadata key in the dotted form familyName.groupName.tagName where familyName may be one of exif, iptc or xmp. Raises:KeyError – if the tag with the given key doesn’t exist

__getitem__(key)

Get a metadata tag for a given key.

Parameters:key (string) – metadata key in the dotted form familyName.groupName.tagName where familyName may be one of exif, iptc or xmp. Raises:KeyError – if the tag doesn’t exist

__setitem__(key, tag_or_value)

Set a metadata tag for a given key. If the tag was previously set, it is overwritten. As a handy shortcut, a value may be passed instead of a fully formed tag. The corresponding tag object will be instantiated.

Parameters:

• key (string) – metadata key in the dotted form familyName.groupName.tagName where familyName may be one of exif, iptc or xmp.
• tag_or_value (pyexiv2.exif.ExifTag or pyexiv2.iptc.IptcTag or pyexiv2.xmp.XmpTag or any valid value type) – an instance of the corresponding family of metadata tag, or a value

Raises:

KeyError – if the key is invalid

buffer

The image buffer as a string. If metadata has been modified, the data won’t be up-to-date until write() has been called.

comment

The image comment.

copy(other, exif=True, iptc=True, xmp=True, comment=True)

Copy the metadata to another image. The metadata in the destination is overridden. In particular, if the destination contains e.g. EXIF data and the source doesn’t, it will be erased in the destination, unless explicitly omitted.

Parameters:

• other (pyexiv2.metadata.ImageMetadata) – the destination metadata to copy to (it must have been read() beforehand)
• exif (boolean) – whether to copy the EXIF metadata
• iptc (boolean) – whether to copy the IPTC metadata
• xmp (boolean) – whether to copy the XMP metadata
• comment (boolean) – whether to copy the image comment

dimensions

A tuple containing the width and height of the image, expressed in pixels.

exif_keys

List of the keys of the available EXIF tags.

classmethod from_buffer(buffer)

Instantiate an image container from an image buffer.

Parameters:buffer (string) – a buffer containing image data

iptc_charset

An optional character set the IPTC data is encoded in.

iptc_keys

List of the keys of the available IPTC tags.

mime_type

The mime type of the image, as a string.

previews

List of the previews available in the image, sorted by increasing size.

read()

Read the metadata embedded in the associated image. It is necessary to call this method once before attempting to access the metadata (an exception will be raised if trying to access metadata before calling this method).

write(preserve_timestamps=False)

Write the metadata back to the image.

Parameters:preserve_timestamps (boolean) – whether to preserve the file’s original timestamps (access time and modification time)

xmp_keys

List of the keys of the available XMP tags.

pyexiv2.exif

exception pyexiv2.exif.ExifValueError(value, type)

Exception raised when failing to parse the value of an EXIF tag.

Attribute value:  the value that fails to be parsed Attribute type:the EXIF type of the tag

class pyexiv2.exif.ExifTag(key, value=None, _tag=None)

An EXIF tag.

Here is a correspondance table between the EXIF types and the possible python types the value of a tag may take:

• Ascii: datetime.datetime, datetime.date, string
• Byte, SByte: string
• Comment: string
• Long, SLong: [list of] long
• Short, SShort: [list of] int
• Rational, SRational: [list of] fractions.Fraction if available (Python ≥ 2.6) or pyexiv2.utils.Rational
• Undefined: string

description

The description of the tag.

human_value

A (read-only) human-readable representation of the value of the tag.

key

The key of the tag in the dotted form familyName.groupName.tagName where familyName = exif.

label

The title (label) of the tag.

name

The name of the tag (this is also the third part of the key).

raw_value

The raw value of the tag as a string.

section_description

The description of the tag’s section.

section_name

The name of the tag’s section.

type

The EXIF type of the tag (one of Ascii, Byte, SByte, Comment, Short, SShort, Long, SLong, Rational, SRational, Undefined).

value

The value of the tag as a python object.

class pyexiv2.exif.ExifThumbnail(_metadata)

A thumbnail image optionally embedded in the IFD1 segment of the EXIF data.

The image is either a TIFF or a JPEG image.

data

The raw thumbnail data. Setting it is restricted to a buffer in the JPEG format.

erase()

Delete the thumbnail from the EXIF data. Removes all Exif.Thumbnail.*, i.e. Exif IFD1 tags.

extension

The file extension of the preview image with a leading dot (e.g. .jpg).

mime_type

The mime type of the preview image (e.g. image/jpeg).

set_from_file(path)

Set the EXIF thumbnail to the JPEG image path. This sets only the Compression, JPEGInterchangeFormat and JPEGInterchangeFormatLength tags, which is not all the thumbnail EXIF information mandatory according to the EXIF standard (but it is enough to work with the thumbnail).

Parameters:path (string) – path to a JPEG file to set the thumbnail to

write_to_file(path)

Write the thumbnail image to a file on disk. The file extension will be automatically appended to the path.

Parameters:path (string) – path to write the thumbnail to (without an extension)

pyexiv2.iptc

exception pyexiv2.iptc.IptcValueError(value, type)

Exception raised when failing to parse the value of an IPTC tag.

Attribute value:  the value that fails to be parsed Attribute type:the IPTC type of the tag

class pyexiv2.iptc.IptcTag(key, values=None, _tag=None)

An IPTC tag.

This tag can have several values (tags that have the repeatable property).

Here is a correspondance table between the IPTC types and the possible python types the value of a tag may take:

• Short: int
• String: string
• Date: datetime.date
• Time: datetime.time
• Undefined: string

description

The description of the tag.

key

The key of the tag in the dotted form familyName.groupName.tagName where familyName = iptc.

name

The name of the tag (this is also the third part of the key).

photoshop_name

The Photoshop name of the tag.

raw_value

The raw values of the tag as a list of strings.

record_description

The description of the tag’s record.

record_name

The name of the tag’s record.

repeatable

Whether the tag is repeatable (accepts several values).

title

The title (label) of the tag.

type

The IPTC type of the tag (one of Short, String, Date, Time, Undefined).

value

The values of the tag as a list of python objects.

pyexiv2.xmp

pyexiv2.xmp.register_namespace(name, prefix)

Register a custom XMP namespace.

Overriding the prefix of a known or previously registered namespace is not allowed.

Parameters:

• name (string) – the name of the custom namespace (ending with a /), typically a URL (e.g. http://purl.org/dc/elements/1.1/)
• prefix (string) – the prefix for the custom namespace (keys in this namespace will be in the form Xmp.{prefix}.{something})

Raises:

• ValueError – if the name doesn’t end with a /
• KeyError – if a namespace already exist with this prefix

pyexiv2.xmp.unregister_namespace(name)

Unregister a custom XMP namespace.

A custom namespace is identified by its name, not by its prefix.

Attempting to unregister an unknown namespace raises an error, as does attempting to unregister a builtin namespace.

Parameters:

name (string) – the name of the custom namespace (ending with a /), typically a URL (e.g. http://purl.org/dc/elements/1.1/)

Raises:

• ValueError – if the name doesn’t end with a /
• KeyError – if the namespace is unknown or a builtin namespace

pyexiv2.xmp.unregister_namespaces()

Unregister all custom XMP namespaces.

Builtin namespaces are not unregistered.

This function always succeeds.

exception pyexiv2.xmp.XmpValueError(value, type)

Exception raised when failing to parse the value of an XMP tag.

Attribute value:  the value that fails to be parsed Attribute type:the XMP type of the tag

class pyexiv2.xmp.XmpTag(key, value=None, _tag=None)

An XMP tag.

Here is a correspondance table between the XMP types and the possible python types the value of a tag may take:

• alt, bag, seq: list of the contained simple type
• lang alt: dict of (language-code: value)
• Boolean: boolean
• Colorant: [not implemented yet]
• Date: datetime.date, datetime.datetime
• Dimensions: [not implemented yet]
• Font: [not implemented yet]
• GPSCoordinate: pyexiv2.utils.GPSCoordinate
• Integer: int
• Locale: [not implemented yet]
• MIMEType: 2-tuple of strings
• Rational: fractions.Fraction if available (Python ≥ 2.6) or pyexiv2.utils.Rational
• Real: [not implemented yet]
• AgentName, ProperName, Text: unicode string
• Thumbnail: [not implemented yet]
• URI, URL: string
• XPath: [not implemented yet]

description

The description of the tag.

key

The key of the tag in the dotted form familyName.groupName.tagName where familyName = xmp.

name

The name of the tag (this is also the third part of the key).

raw_value

The raw value of the tag as a [list of] string(s).

title

The title (label) of the tag.

type

The XMP type of the tag.

value

The value of the tag as a [list of] python object(s).

pyexiv2.preview

class pyexiv2.preview.Preview(preview)

A preview image (properties and data buffer) embedded in image metadata.

data

The preview image data buffer.

dimensions

A tuple containing the width and height of the preview image in pixels.

extension

The file extension of the preview image with a leading dot (e.g. .jpg).

mime_type

The mime type of the preview image (e.g. image/jpeg).

size

The size of the preview image in bytes.

write_to_file(path)

Write the preview image to a file on disk. The file extension will be automatically appended to the path.

Parameters:path (string) – path to write the preview to (without an extension)

pyexiv2.utils

pyexiv2.utils.undefined_to_string(undefined)

Convert an undefined string into its corresponding sequence of bytes. The undefined string must contain the ascii codes of a sequence of bytes, separated by white spaces (e.g. “48 50 50 49” will be converted into “0221”). The Undefined type is part of the EXIF specification.

Parameters:undefined (string) – an undefined string Returns:the corresponding decoded string Return type:string

pyexiv2.utils.string_to_undefined(sequence)

Convert a string into its undefined form. The undefined form contains a sequence of ascii codes separated by white spaces (e.g. “0221” will be converted into “48 50 50 49”). The Undefined type is part of the EXIF specification.

Parameters:sequence (string) – a sequence of bytes Returns:the corresponding undefined string Return type:string

pyexiv2.utils.make_fraction(*args)

Make a fraction.

The type of the returned object depends on the availability of the fractions module in the standard library (Python ≥ 2.6).

Raises:TypeError – if the arguments do not match the expected format for a fraction

class pyexiv2.utils.Rational(numerator, denominator)

A class representing a rational number.

Its numerator and denominator are read-only properties.

Do not use this class directly to instantiate a rational number. Instead, use make_fraction().

__eq__(other)

Compare two rational numbers for equality.

Two rational numbers are equal if their reduced forms are equal.

Parameters:other (Rational) – the rational number to compare to self for equality Returns:True if equal, False otherwise Return type:boolean

__repr__()

Returns:the official string representation of the object Return type:string

__str__()

Returns:a string representation of the rational number Return type:string

denominator

The denominator of the rational number.

static from_string(string)

Instantiate a Rational from a string formatted as [-]numerator/denominator.

Parameters:string (string) – a string representation of a rational number Returns:the rational number parsed Return type:Rational Raises:ValueError – if the format of the string is invalid

numerator

The numerator of the rational number.

to_float()

Returns:a floating point number approximation of the value Return type:float

class pyexiv2.utils.GPSCoordinate(degrees, minutes, seconds, direction)

A class representing GPS coordinates (e.g. a latitude or a longitude).

Its attributes (degrees, minutes, seconds, direction) are read-only properties.

__eq__(other)

Compare two GPS coordinates for equality.

Two coordinates are equal if and only if all their components are equal.

Parameters:other (GPSCoordinate) – the GPS coordinate to compare to self for equality Returns:True if equal, False otherwise Return type:boolean

__str__()

Returns:a string representation of the GPS coordinate conforming to the XMP specification Return type:string

degrees

The degrees component of the coordinate.

direction

The direction component of the coordinate.

static from_string(string)

Instantiate a GPSCoordinate from a string formatted as DDD,MM,SSk or DDD,MM.mmk where DDD is a number of degrees, MM is a number of minutes, SS is a number of seconds, mm is a fraction of minutes, and k is a single character N, S, E, W indicating a direction (north, south, east, west).

Parameters:string (string) – a string representation of a GPS coordinate Returns:the GPS coordinate parsed Return type:GPSCoordinate Raises:ValueError – if the format of the string is invalid

minutes

The minutes component of the coordinate.

seconds

The seconds component of the coordinate.