Object Storage Service:Download progress bars

Usage notes

• In this topic, the public endpoint of the China (Hangzhou) region is used. If you want to access OSS from other Alibaba Cloud services in the same region as OSS, use an internal endpoint. For more information about OSS regions and endpoints, see Regions, endpoints and open ports.

• In this topic, access credentials are obtained from environment variables. For more information about how to configure access credentials, see Configure access credentials.

• In this topic, an OSSClient instance is created by using an OSS endpoint. If you want to create an OSSClient instance by using custom domain names or Security Token Service (STS), see Initialization.

Examples

The following sample code provides an example on how to use a progress bar when you use bucket.get_object_to_file to download an object:

# -*- coding: utf-8 -*-
from __future__ import print_function
import os
import sys
import oss2
from oss2.credentials import EnvironmentVariableCredentialsProvider
# Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
auth = oss2.ProviderAuthV4(EnvironmentVariableCredentialsProvider())

# Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. 
endpoint = "https://oss-cn-hangzhou.aliyuncs.com"

# Specify the ID of the region that maps to the endpoint. Example: cn-hangzhou. This parameter is required if you use the signature algorithm V4.
region = "cn-hangzhou"

# Specify the name of your bucket. 
bucket = oss2.Bucket(auth, endpoint, "yourBucketName", region=region)

# If Content-Length is not in the HTTP response headers, the value of total_bytes is None. 
# consumed_bytes specifies the size of data that has been downloaded. Unit: bytes. 
# total_bytes specifies the total size of the object that you want to download. Unit: bytes.
def percentage(consumed_bytes, total_bytes):
    if total_bytes:
        rate = int(100 * (float(consumed_bytes) / float(total_bytes)))
        # rate specifies the download progress. 
        print('\r{0}% '.format(rate), end='')

        sys.stdout.flush()

# progress_callback is an optional parameter used to return progress information. 
bucket.get_object_to_file('yourObjectName', 'yourLocalFile', progress_callback=percentage)

References

For the complete sample code for configuring progress bars for object download tasks, visit GitHub.