AIOFile

Zusammenfassung

Contains methods that perform file-related operations such as seek, tell, read, and write.

Diskussion

This class cannot be instantiated directly. An instance of this class is returned by the AIO object's open method.

Eigenschaften

Eigenschaft	Erläuterung	Datentyp
cloud (Schreibgeschützt)	An instance of a class that has cloud-specific methods. It is used to retrieve details of the cloud store that was used when the AIOFile object was created. Returns an CloudFileOp object. cloud_io = AIO(r"C:\data\datacloud.acs") rcsfile = cloud_io.open(r'testfile.txt', 'r') rcsfile.cloud.clearcache()	Object

Methodenübersicht

Methode	Erläuterung
close ()	Flushes and closes the open file handle.
flush ()	Flushes the write buffers of the file.
read (size)	Reads data from an object and returns binary or text depending on the opened items.
rewind ()	Resets the stream position to the start.
seek (offset, {whence})	Changes the stream position to the specified byte offset.
tell ()	Returns the current stream position.
write (b)	Writes data to a local file or cloud object.

Methoden

close ()

For cloud stores, the cloud BLOBs are generated at closing.

rcsfile = cloud_io.open(r'cog.txt', 'r')
rcsfile.close()

flush ()

rcsfile = cloud_io.open(r'cog.txt', 'r')
rcsfile.flush()

read (size)

Parameter	Erläuterung	Datentyp
size	The number of bytes that will be read. A value of -1 reads all the content.	Integer

Rückgabewert

Datentyp	Erläuterung
String	Returns binary or text (bytes or string) depending on the opened items.

from arcpy import AIO
cloud_io = AIO(r"C:\data\datacloud.acs")
rcsfile = cloud_io.open(r'testfile.txt', 'r')
rcsfile.read(size=4)
rcsfile.close()

from arcpy import AIO
cloud_io = AIO(r"C:\data\datacloud.acs")
with cloud_io.open(r'testfile.txt', 'r') as rcsfile:
    rcsfile.read(size=4)

rewind ()

cloud_io = AIO(r"C:\data\datacloud.acs")
rcsfile = cloud_io.open(r'testfile.txt', 'r')
rcsfile.rewind()

seek (offset, {whence})

Parameter	Erläuterung	Datentyp
offset	The number of bytes that will be read. A value of -1 reads all the content. (Der Standardwert ist -1)	Integer
whence	Specifies how the file position indicator will be set. os.SEEK_SET—The position will be set relative to the beginning of the file. os.SEEK_CUR—The position will be set relative to the current file position. os.SEEK_END—The position will be set relative to the end of the file. A nonzero value for os.SEEK_CUR or os.SEEK_END is not supported for local files when the file is opened in a nonbinary mode.	Object

import os
rcsfile = cloud_io.open(r'cog.txt', 'r')
rcsfile.seek(offset=6, whence=os.SEEK_CUR)

tell ()

Rückgabewert

Datentyp	Erläuterung
Integer	The current stream position.

rcsfile = cloud_io.open(r'cog.tif', 'rb')
print(rcsfile.tell())

write (b)

Parameter	Erläuterung	Datentyp
b	The data that will be written.	String

Rückgabewert

Datentyp	Erläuterung
Integer	The number of bytes written.

from arcpy import AIO
local_io = AIO(r"C:\data")
rcsfile = local_io.open(r'testfile.txt', 'r')
rcsfile.write("This is a test file.")
rcsfile.close()

from arcpy import AIO
cloud_io = AIO(r"C:\data\datacloud.acs")
rcsfile = cloud_io.open(r"C:\data\info\datafile.txt", 'w', mime={'Content-Type': 'text/plain'})
rcsfile.write("This is a test file.")
rcsfile.close()

# Using with statement (context manager to close the opened file)
cloud_io = AIO(r"C:\data\datacloud.acs")
with cloud_io.open(r"C:\data\info\datafile.txt", 'w', mime={'Content-Type': 'text/plain'}) as rcsfile:
    rcsfile.write("This is a test file.")