How Do I Specify Content-SHA256? (SDK for Python)

You can upload the x-obs-content-sha256 header when uploading an object or a part. The value of this header is the hexadecimal value converted from the SHA256 value of the request body and is calculated from Hex(SHA256Hash(<payload>). The server calculates and verifies the SHA256 value of the message body in the request with x-obs-content-sha256 included, which may make performance deteriorate, but is recommended for security purposes. Sample code for uploading an object is as follows:

# -*- coding:utf-8 -*-
# This example uploads a file with content-sha256 specified.
from obs import ObsClient
import os
import traceback
import hashlib
# Obtain an AK and SK pair using environment variables or import the AK and SK pair in other ways. Using hard coding may result in leakage.
# Obtain an AK and SK pair from the management console by referring to https://support.huaweicloud.com/intl/en-us/usermanual-ca/ca_01_0003.html.
ak = os.getenv("AccessKeyID")
sk = os.getenv("SecretAccessKey")
# (Optional) If you use a temporary AK and SK pair and a security token to access OBS, obtain them from environment variables.
security_token = os.getenv("SecurityToken")
# Set server to the endpoint corresponding to the bucket. CN-Hong Kong is used here as an example. Replace it with the one currently in use.
server = "https://obs.ap-southeast-1.myhuaweicloud.com"
#  Calculate SHA256 of the file.
def getSha256(file_path):
    # Read the file content in binary mode.
    with open(file_path, 'rb') as f:
        # Create an SHA256 hash object.
        sha256_hash = hashlib.sha256()
        # Read the file content cyclically and update the hash value.
        while True:
            data = f.read(65536)  # Read 64 KB each time.
            if not data:
                break
            sha256_hash.update(data)
    # Return the hexadecimal representation of the hash value.
    sha256 = sha256_hash.hexdigest()
    f.close()
    return sha256
# Create an obsClient instance.
# If you use a temporary AK and SK pair and a security token to access OBS, you must specify security_token when creating an instance.
obsClient = ObsClient(access_key_id=ak, secret_access_key=sk, server=server)
bucketName = 'examplebucket'
objectKey = 'example/objectname1'
file_path = 'D:\\example.txt'
# Specify the user-defined header.
extensionHeaders = {'x-obs-content-sha256': getSha256(file_path)}
try:
    # Upload a file.
    resp = obsClient.putFile(bucketName, objectKey, file_path, extensionHeaders=extensionHeaders)
    # If status code 2xx is returned, the API is called successfully. Otherwise, the API call fails.
    if resp.status < 300:
        print('Put File Succeeded')
        print('requestId:', resp.requestId)
        print('etag:', resp.body.etag)
        print('versionId:', resp.body.versionId)
    else:
        print('Put File Failed')
        print('requestId:', resp.requestId)
        print('errorCode:', resp.errorCode)
        print('errorMessage:', resp.errorMessage)
except:
    print(traceback.format_exc())

Python SDK supports integrity check with both MD5 and SHA256 (recommended for security purposes).