Python 3: create in-memory Zipfile with in-memory Xml - python-3.x

I am trying to create xml file with io.StringIO() and pack it into ZipFile, but the output is an empty zip file. Where is a mistake?
string_xml_buffer = io.StringIO()
string_xml_buffer.write('<MyContent>')
string_xml_buffer.write('</MyContent>')
bytes_zip_buffer = io.BytesIO()
zf = ZipFile(bytes_zip_buffer, mode = 'w')
zf.writestr('filename.xml', string_xml_buffer.getvalue())
# Django response
response = HttpResponse(zf, content_type='application/zip')
response['Content-Disposition'] = 'attachment; filename="f.zip"'
return response

the problem was in missing zf.close(). With this row the code works great.

Related

AWS Object Lambda using PyPDF2 to send back encrypted PDF

My AWS OBJECT Lambda Function gets an unencrypted PDF via the Object Lambda inputS3Url. I want to use PyPDF2 to convert this to encrypted PDF, and send back via s3.write_get_object_response. How do I do this?
s3_url = object_get_context["inputS3Url"]
url=s3_url
response = requests.get(url)
my_raw_data = response.content
[SAVE ENCRYPTED my_raw_data TO VARIABLE so it can returned via S3.write_get_object_response - HOW?]
s3 = boto3.client('s3')
s3.write_get_object_response(
Body= [WHAT WOULD GO HERE?]
RequestRoute=request_route,
RequestToken=request_token)
The docs got you! Encrypting PDFs and Streaming Data is what you need (at least if I got you right; let me know if you want to achieve something else than getting a password-protected PDF on S3)
Not tested, but something like this
from PyPDF2 import PdfReader, PdfWriter
from io import BytesIO
reader = PdfReader(BytesIO(my_raw_data))
writer = PdfWriter()
# Add all pages to the writer
for page in reader.pages:
writer.add_page(page)
# Add a password to the new PDF
writer.encrypt("my-secret-password")
# Save the new PDF to a file
with BytesIO() as bytes_stream:
writer.write(bytes_stream)
bytes_stream.seek(0)
s3 = boto3.client('s3')
s3.write_get_object_response(
Body=bytes_stream,
RequestRoute=request_route,
RequestToken=request_token
)

File streaming in python [duplicate]

I need to create a CSV and upload it to an S3 bucket. Since I'm creating the file on the fly, it would be better if I could write it directly to S3 bucket as it is being created rather than writing the whole file locally, and then uploading the file at the end.
Is there a way to do this? My project is in Python and I'm fairly new to the language. Here is what I tried so far:
import csv
import csv
import io
import boto
from boto.s3.key import Key
conn = boto.connect_s3()
bucket = conn.get_bucket('dev-vs')
k = Key(bucket)
k.key = 'foo/foobar'
fieldnames = ['first_name', 'last_name']
writer = csv.DictWriter(io.StringIO(), fieldnames=fieldnames)
k.set_contents_from_stream(writer.writeheader())
I received this error: BotoClientError: s3 does not support chunked transfer
UPDATE: I found a way to write directly to S3, but I can't find a way to clear the buffer without actually deleting the lines I already wrote. So, for example:
conn = boto.connect_s3()
bucket = conn.get_bucket('dev-vs')
k = Key(bucket)
k.key = 'foo/foobar'
testDict = [{
"fieldA": "8",
"fieldB": None,
"fieldC": "888888888888"},
{
"fieldA": "9",
"fieldB": None,
"fieldC": "99999999999"}]
f = io.StringIO()
fieldnames = ['fieldA', 'fieldB', 'fieldC']
writer = csv.DictWriter(f, fieldnames=fieldnames)
writer.writeheader()
k.set_contents_from_string(f.getvalue())
for row in testDict:
writer.writerow(row)
k.set_contents_from_string(f.getvalue())
f.close()
Writes 3 lines to the file, however I'm unable to release memory to write a big file. If I add:
f.seek(0)
f.truncate(0)
to the loop, then only the last line of the file is written. Is there any way to release resources without deleting lines from the file?
I did find a solution to my question, which I will post here in case anyone else is interested. I decided to do this as parts in a multipart upload. You can't stream to S3. There is also a package available that changes your streaming file over to a multipart upload which I used: Smart Open.
import smart_open
import io
import csv
testDict = [{
"fieldA": "8",
"fieldB": None,
"fieldC": "888888888888"},
{
"fieldA": "9",
"fieldB": None,
"fieldC": "99999999999"}]
fieldnames = ['fieldA', 'fieldB', 'fieldC']
f = io.StringIO()
with smart_open.smart_open('s3://dev-test/bar/foo.csv', 'wb') as fout:
writer = csv.DictWriter(f, fieldnames=fieldnames)
writer.writeheader()
fout.write(f.getvalue())
for row in testDict:
f.seek(0)
f.truncate(0)
writer.writerow(row)
fout.write(f.getvalue())
f.close()
Here is a complete example using boto3
import boto3
import io
session = boto3.Session(
aws_access_key_id="...",
aws_secret_access_key="..."
)
s3 = session.resource("s3")
buff = io.BytesIO()
buff.write("test1\n".encode())
buff.write("test2\n".encode())
s3.Object(bucket, keypath).put(Body=buff.getvalue())
We were trying to upload file contents to s3 when it came through as an InMemoryUploadedFile object in a Django request. We ended up doing the following because we didn't want to save the file locally. Hope it helps:
#action(detail=False, methods=['post'])
def upload_document(self, request):
document = request.data.get('image').file
s3.upload_fileobj(document, BUCKET_NAME,
DESIRED_NAME_OF_FILE_IN_S3,
ExtraArgs={"ServerSideEncryption": "aws:kms"})
According to docs it's possible
s3.Object('mybucket', 'hello.txt').put(Body=open('/tmp/hello.txt', 'rb'))
so we can use StringIO in ordinary way
Update: smart_open lib from #inquiring minds answer is better solution
There's an interesting code solution mentioned in a GitHub smart_open issue (#82) that I've been meaning to try out. Copy-pasting here for posterity... looks like boto3 is required:
csv_data = io.BytesIO()
writer = csv.writer(csv_data)
writer.writerows(my_data)
gz_stream = io.BytesIO()
with gzip.GzipFile(fileobj=gz_stream, mode="w") as gz:
gz.write(csv_data.getvalue())
gz_stream.seek(0)
s3 = boto3.client('s3')
s3.upload_fileobj(gz_stream, bucket_name, key)
This specific example is streaming to a compressed S3 key/file, but it seems like the general approach -- using the boto3 S3 client's upload_fileobj() method in conjunction with a target stream, not a file -- should work.
There's a well supported library for doing just this:
pip install s3fs
s3fs is really trivial to use:
import s3fs
s3fs.S3FileSystem(anon=False)
with s3.open('mybucket/new-file', 'wb') as f:
f.write(2*2**20 * b'a')
f.write(2*2**20 * b'a')
Incidentally there's also something built into boto3 (backed by the AWS API) called MultiPartUpload.
This isn't factored as a python stream which might be an advantage for some people. Instead you can start an upload and send parts one at a time.
To write a string to an S3 object, use:
s3.Object('my_bucket', 'my_file.txt').put('Hello there')
So convert the stream to string and you're there.

Saving data in Selenium

I am trying to save output data after I am running successful script in python using Selenium. But, I am not able to save result at end of my run/ script. My code is running fine, only problem is I am not able to save out to a file which can be .json, csv or text. I need serious help on this one.
from selenium import webdriver
from bs4 import BeautifulSoup as bs
import csv
import requests
# saving data in bangkok_vendor.text
def copy_info():
with open('bangkok_vendor.text','a') as wt:
for x in script3:
wt.write(x)
wt.close()
return
contents =[]
filename = 'link_business_filter.csv'
with open(filename,'rt') as f:
data = csv.reader(f)
for row in data:
links = row[0]
contents.append(links)
for link in contents:
url_html = requests.get(link)
print(link)
browser = webdriver.Chrome('chromedriver')
open = browser.get(link)
source = browser.page_source
data = bs(source,"html.parser")
body = data.find('body')
script = body
x_path = '//*[#id="react-root"]/section/main/div'
script2 = browser.find_element_by_xpath(x_path)
script3 = script2.text
#script2.send_keys(keys.COMMAND + 't')
browser.close()
print(script3)
copy_info()
Did you try using csv.writer for csv files? Please check out the following link. hope it helps.
Save results to csv file with Python

Saving selenium results/output at run time in text file using Python

I am running a script in Python3 using Selenium. I am getting my output what I expected. Now, I want to save my output to a text, or csv or json file. When I am trying to run my script and save result to a file I am getting an Error with open('bangkok_vendor.txt','a') as wt :
TypeError: 'NoneType' object is not callable
Which means loop in the program runs only one time and does not store data in file called bangkok_vendor.txt. In normal python scraper programs it would n't have any problem storing data but this is first time I am using selenium. Can you please help me with solution thanks.
I am trying to run this script from my terminal command and output is what to save to any file format :
from selenium import webdriver
from bs4 import BeautifulSoup as bs
import csv
import requests
contents =[]
filename = 'link_business_filter.csv'
def copy_json():
with open("bangkok_vendor.text",'w') as wt:
for x in script2:
wt.writer(x)
wt.close()
with open(filename,'rt') as f:
data = csv.reader(f)
for row in data:
links = row[0]
contents.append(links)
for link in contents:
url_html = requests.get(link)
print(link)
browser = webdriver.Chrome('chromedriver')
open = browser.get(link)
source = browser.page_source
data = bs(source,"html.parser")
body = data.find('body')
script = body
x_path = '//*[#id="react-root"]/section/main/div'
script2 = browser.find_element_by_xpath(x_path)
script3 = script2.text
#script2.send_keys(keys.COMMAND + 't')
browser.close()
print(script3)
You need to pass script2 as a parameter for copy_json function and call it when you extract the data from the page.
Change write mode to append, otherwise the file will be reset every time you call copy_json function.
Dont overwrite built-in functions like open, otherwise you won't be able to open a file to write data once you move onto the second iteration.
I refactored your code a bit:
LINK_CSV = 'link_business_filter.csv'
SAVE_PATH = 'bangkok_vendor.txt'
def read_links():
links = []
with open(LINK_CSV) as f:
reader = csv.reader(f)
for row in reader:
links.append(row[0])
return links
def write_data(data):
with open(SAVE_PATH, mode='a') as f:
f.write(data + "\n")
if __name__ == '__main__':
browser = webdriver.Chrome('chromedriver')
links = read_links()
for link in links:
browser.get(link)
# You may have to wait a bit here
# until the page is loaded completely
html = browser.page_source
# Not sure what you're trying to do with body
# soup = BeautifulSoup(html, "html.parser")
# body = soup.find('body')
x_path = '//*[#id="react-root"]/section/main/div'
main_div = browser.find_element_by_xpath(x_path)
text = main_div.text
write_data(text)
# close browser after every link is processed
browser.quit()

tmp file in Google cloud Functions for Python

Python runs like a charm on google cloud functions, but for the tmp files. Here's my simplified code:
FILE_PATH = "{}/report.pdf".format(tempfile.gettempdir())
pdf.output(FILE_PATH)
...
with open(FILE_PATH,'rb') as f:
data = f.read()
f.close()
encoded = base64.b64encode(data).decode()
attachment = Attachment()
attachment.content = str(encoded)
attachment.type = "application/pdf"
attachment.filename = "report"
attachment.disposition = "attachment"
attachment.content_id = "Report"
mail = Mail(from_email, subject, to_email, content)
mail.add_attachment(attachment)
Error is: [Errno 2] No such file or directory: '/tmp/report.pdf'
It works perfectly fine locally. Docs unfortunately only shows the node version. Workarounds would also be fine for sending that PDF.
It is a little difficult to find Google official documentation for writing in temporary folder. In My case, I needed to write in a temporary directory and upload it to google cloud storage using GCF.
Writing in temporary directory of Google Cloud Functions, it will consume memory resources provisioned for the function.
After creating the file and using it, it is recommended to remove it from the temporary directory. I used this code snippet for Write a csv into a temp dir in GCF(Python 3.7).
import pandas as pd
import os
import tempfile
from werkzeug.utils import secure_filename
def get_file_path(filename):
file_name = secure_filename(filename)
return os.path.join(tempfile.gettempdir(), file_name)
def write_temp_dir():
data = [['tom', 10], ['nick', 15]]
df = pd.DataFrame(data, columns = ['Name', 'Age'])
name = 'example.csv'
path_name = get_file_path(name)
df.to_csv(path_name, index=False)
os.remove(path_name)

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