Internal server error 500 in python - javascript

I have checked all cgi related thing, but still I am getting this error.
I tried to run other sample program which get response from .py file. Which works fine, but for this code only it gives :
GET http://localhost/testapp/demos/classifier_demo.py?query= 500 (Internal Server Error)x.ajaxTransport.n.send # jquery-1.10.2.min.js:6x.extend.ajax # jquery-1.10.2.min.js:6call_fun # demo.html:16
jquery-1.10.2.min.js:6 GET http://localhost/testapp/demos/classifier_demo.py?query=EASTERN. 500 (Internal Server Error)x.ajaxTransport.n.send # jquery-1.10.2.min.js:6x.extend.ajax # jquery-1.10.2.min.js:6call_fun # demo.html:16
P.S I have already set the permission 777
I am calling python script using jquery every 5 seconds.
<script>
$( document ).ready(function() {
function call_fun() {
var text = $('textarea#trans').val();
//alert(text)
var data = {"query" : text};
//alert(data);
$.ajax({
url: "classifier_demo.py",
type: "POST",
data: data,
success: function(response) {
console.log(response)
}
})
}
setInterval(call_fun, 5000);
});
</script>
here is the python code:
#!/usr/bin/python
"""
Using the words as features removing stopwords
"""
from sklearn.utils import check_random_state
from sklearn.datasets import load_files
from sklearn.feature_extraction.text import TfidfVectorizer
from sklearn.feature_extraction.text import HashingVectorizer
from sklearn.naive_bayes import MultinomialNB
from sklearn.feature_extraction.text import CountVectorizer
from sklearn.metrics import accuracy_score, average_precision_score, f1_score, precision_score, recall_score
from sklearn.externals import joblib
from sklearn.feature_extraction.text import FeatureHasher
from nltk.corpus import stopwords
from nltk.stem.lancaster import LancasterStemmer
from nltk.tokenize import word_tokenize
import nltk
import numpy as np
from time import time
import pprint, pickle
import gearman
import nltk, json, cgi
import re
import os
import sys
"""
This class will train and test the data and will give polarity for various emotions
"""
class SentimentAnalyzer(object):
"""
Init for SentimentAnalyzer
"""
def __init__(self):
self.root_dir = os.getcwd()
self.trainClassifier()
"""
Function to fetch the data from cache
#cache <dict> consist of training data
"""
def fetch_data(self, cache, data_home=None, subset='train', categories=None,
shuffle=True, random_state=42):
if subset in ('train', 'test'):
data = cache[subset]
else:
raise ValueError(
"subset can only be 'train', 'test' or 'all', got '%s'" % subset)
if shuffle:
random_state = check_random_state(random_state)
indices = np.arange(data.target.shape[0])
random_state.shuffle(indices)
data.filenames = data.filenames[indices]
data.target = data.target[indices]
# Use an object array to shuffle: avoids memory copy
data_lst = np.array(data.data, dtype=object)
data_lst = data_lst[indices]
data.data = data_lst.tolist()
return data
"""
For custom tokenizing the text, removed stop words from text
#text <type 'str'> text which needs to get tokenized
#return <type 'str'> tokens
"""
def token_ques(self, text):
things_to_replace = ['?']
#wh_tags = ['WP','WRB','MD','WDT']
things_to_replace += stopwords.words('english')
#wh_word = None
for tok in text.split('\n'):
original_query = tok
query_pos_tags = nltk.pos_tag(word_tokenize(tok))
for word in things_to_replace:
tok = tok.lower()
tok = re.sub("\s"+word+"\s|\s?"+"\?"+"$",' ',tok)
tok = tok.strip(" ")
tok = tok.lstrip(" ")
tok = tok.rstrip(" ")
for word in word_tokenize(tok):
yield word.lower()
"""
Train classifier
"""
def trainClassifier(self):
try:
t1 = time()
start_time = time()
self.hasher = FeatureHasher(input_type='string',non_negative=True)
self.clf = MultinomialNB(alpha=0.001)
self.hasher = FeatureHasher(input_type='string',non_negative=True)
self.clf = MultinomialNB(alpha=0.001)
data_folder = self.root_dir + "/emotions"
train_dataset = load_files(data_folder)
print("Time taken to load the data=>", time()-start_time)
print("data loaded")
cache = dict(train=train_dataset)
self.data_train = self.fetch_data(cache, subset='train')
try:
X_train = pickle.load(open("x_result.pickle", "rb" ) )
y_train = pickle.load(open("y_result.pickle", "rb" ) )
self.clf.fit(X_train, y_train)
except:
print "Updating the classifier"
training_data = []
for text in self.data_train.data:
#text = self.modifyQuery(text.decode('utf-8','ignore'))
text = text.decode('utf-8','ignore')
training_data.append(text)
raw_X = (self.token_ques(text) for text in training_data) #Type of raw_X <type 'generator'>
#X_train = self.vectorizer.fit_transform(raw_X)
X_train = self.hasher.transform(raw_X)
y_train = self.data_train.target
readx = open('x_result.pickle', 'wb')
pickle.dump(X_train, readx)
readx.close()
readY = open('y_result.pickle', 'wb')
pickle.dump(y_train, readY)
readY.close()
self.clf.fit(X_train, y_train)
print("Classifier tained ...")
print("time taken=>", time()-t1)
except Exception:
import traceback
print traceback.format_exc()
"""
Function to test classifier
"""
def testClassifier(self, query):
try:
result = {}
#To replace NE
#query = self.modifyQuery(query)
test_data = [query]
raw_X = (self.token_ques(text) for text in test_data)
X_test = self.hasher.transform(raw_X)
#X_test = self.vectorizer.fit_transform(raw_X)
pred = self.clf.predict(X_test)
print("pred=>", pred)
self.categories = self.data_train.target_names
for doc, category in zip(test_data, pred):
print('%r => %s' % (doc, self.categories[category]))
index = 1
predict_prob = self.clf.predict_proba(X_test)
final_result = []
for doc, category_list in zip(test_data, predict_prob):
# print('\n\n')
category_list = sorted(enumerate(category_list), key=lambda x:x[1], reverse=True)
i = 0
for val in category_list:
if float(val[1]) > float(0.05):
# print('%r => %s => %s' % (doc, self.categories[val[0]], str(val[1])))
result = {}
result[self.categories[val[0]]] = "%0.2f"%(float(val[1]) * 100)+"%"
final_result.append(result)
index += 1
except Exception:
import traceback
print traceback.format_exc()
import json
# print result
# print final_result
return final_result
if __name__ == '__main__':
fs = cgi.FieldStorage()
text = fs['query'].value
#query = fs.getvalue(query)
#query = raw_input("Please enter the text to process:")
query = "Love you man"
result = { "result" : text}
#result = SentimentAnalyzer().testClassifier(query)
json_result = json.dumps( result )
print json_result

Related

combining reactjs frontend with python + flask backend

I have a reactjs frontend that has a react-leaflet map. On click of the map, I can access the latitude and longitude. On this same click, I need to get a Python script to load. I have a Flask endpoint as my backend server, and my react frontend can hit this endpoint, I'm just not sure how to tie everything together and have the Python script load and work properly :(
my React code-
import { useMapEvents, Popup, Marker} from "react-leaflet";
const PopupInfo = () => {
const [markers, setMarkers] = useState([]);
const map = useMapEvents({
async click(e) {
const newMarker = e.latlng
setMarkers([...markers, newMarker])
console.log(e.latlng, "info")
//access coordinates to load the python script
const response = await fetch(`/coordinates?sel_lat=${e.latlng.lat}&sel_lon=${e.latlng.lng}`,
{
method: 'GET',
headers: {
Accept: 'application/json',
}});
console.log(response, 'TESTING PROMISE')
if (!response.ok) {
throw new Error(`Error! status: ${response.status}`);
}
const result = response.json();
console.log('result is: ', JSON.stringify(result, null, 4));
}
})
return (
<>
{markers.map((marker, index) =>
<Marker position={marker} key={index}>
<Popup>Latitude: ({marker.lat})<br></br>Longitude: ({marker.lng})</Popup>
</Marker>)}
</>
);
};
export default PopupInfo;
python code-
import argparse
import time
import pandas as pd
import datetime as dt
import json
from src.bcolors import bcolors as bc
import src.config as cfg
import src.utils as utils
import src.cfsr as cfsr
import src.gfs as gfs
def parse_args():
parser = argparse.ArgumentParser(
description="PURPOSE: Extract current meteorological information\n \
for a location and give climate context",
)
parser.add_argument(
"--sel_lat", type=float, dest="sel_lat", help="Latitude of requested location"
)
parser.add_argument(
"--sel_lon", type=float, dest="sel_lon", help="Longitude of requested location"
)
args = parser.parse_args()
##v2
# print("optional arg is: " + args.sel_lat, args.sel_lon)
return args
def main():
start = time.time()
args = parse_args()
print(f"{bc.HEADER}EXTRACT INFO FOR SELECTED LOCATION{bc.ENDC}")
print(f"{bc.HEADER}({args.sel_lat},{args.sel_lon}){bc.ENDC}")
slat = args.sel_lat
slon = args.sel_lon
slon360 = utils.lon_to_360(args.sel_lon)
if cfg.debug:
fin_ij = utils.get_ij_data(cfg.file_ref, slat, slon360)
print(
f"{bc.BOLD}Selected grid point: {fin_ij.lat.values}, {fin_ij.lon.values}{bc.ENDC}"
)
if cfg.debug:
fin_ij = utils.get_ij_data(cfg.file_ref, slat, slon360)
print(
f"{bc.BOLD}Selected grid point: {fin_ij.lat.values}, {fin_ij.lon.values}{bc.ENDC}"
)
print(f"Elapsed time initialization: {time.time()-start}s")
this_time = time.time()
sdoy = utils.calc_doy_noleap(cfg.today)
print(f"Elapsed time doy: {time.time()-this_time}s")
this_time = time.time()
# Get data for location
sdata_doy = cfsr.get_data_doy_loc(slat, slon360, sdoy)
sdata_all = cfsr.get_data_loc(slat, slon360)
print(f"Elapsed time load sdata: {time.time()-this_time}s")
this_time = time.time()
sqtiles = sdata_doy.sel(time=slice(f"{cfg.bsyear}", f"{cfg.beyear}")).quantile(
cfg.qtiles
)
print(f"Elapsed time qtiles: {time.time()-this_time}s")
this_time = time.time()
fcvars = gfs.get_loc_fcvars(slat, slon360)
print(f"Elapsed time fcvars: {time.time()-this_time}s")
this_time = time.time()
# Loading this year data
sdata_y = cfsr.get_data_this_year_loc(slat, slon360)
shmap_y = cfsr.get_hmap_this_year_loc(slat, slon360)
shwcs_y = cfsr.get_hwcs_this_year_loc(slat, slon360)
# Loading bounds (for max-min plots)
sbounds = cfsr.get_bounds_loc(slat, slon360)
print(f"Elapsed time load sdat_ty: {time.time()-this_time}s")
this_time = time.time()
doy_temp_ptile = (abs(sqtiles - fcvars)).idxmin(dim="quantile") * 100.0
print(f"Elapsed time doy qtile: {time.time()-this_time}s")
this_time = time.time()
print(
f"{bc.OKGREEN}Today's tmax {round(fcvars.tmax.values.item(),1)} at the selected point ({slat},{slon}) will be on the {int(doy_temp_ptile.tmax)}th percentile{bc.ENDC}"
)
print(
f"{bc.OKGREEN}Today's tmin {round(fcvars.tmin.values.item(),1)} at the selected point ({slat},{slon}) will be on the {int(doy_temp_ptile.tmin)}th percentile{bc.ENDC}"
)
print(
f"{bc.OKGREEN}Today's tmed {round(fcvars.tmed.values.item(),1)} at the selected point ({slat},{slon}) will be on the {int(doy_temp_ptile.tmed)}th percentile{bc.ENDC}"
)
#####################################################################
#####################################################################
sdata_doy.drop(["lat", "lon"]).to_dataframe().round(1).to_csv(
f"{cfg.wrk_dir}/temp_doy.csv", index=False
)
sdata_y.drop(["lat", "lon"]).to_dataframe().round(1).to_csv(
f"{cfg.wrk_dir}/temp_current_year.csv", index=True
)
shmap_y.drop(["lat", "lon"]).to_dataframe().round(1).to_csv(
f"{cfg.wrk_dir}/hmap_current_year.csv", index=True
)
shwcs_y.drop(["lat", "lon"]).to_dataframe().round(1).to_csv(
f"{cfg.wrk_dir}/hwcs_current_year.csv", index=True
)
sbounds_time = sbounds.assign_coords(
doy=pd.date_range(
dt.datetime(cfg.today.year, 1, 1),
dt.datetime(cfg.today.year, 12, 31),
freq="D",
)
)
sbounds_time.drop(["lat", "lon"]).to_dataframe().round(1).to_csv(
f"{cfg.wrk_dir}/bounds.csv", index=True
)
fcvars.to_dataframe().round(1).to_csv(f"{cfg.wrk_dir}/fcvars.csv", index=True)
print(f"Elapsed time write csv files: {time.time()-this_time}s")
this_time = time.time()
print(f"{bc.HEADER}Writing out json file with loc info{bc.ENDC}")
loc_stats = {
"tmax": round(fcvars.tmax.values.item(), 1),
"tmin": round(fcvars.tmin.values.item(), 1),
"tmed": round(fcvars.tmed.values.item(), 1),
"tmax_ptile": int(doy_temp_ptile.tmax),
"tmin_ptile": int(doy_temp_ptile.tmin),
"tmed_ptile": int(doy_temp_ptile.tmed),
"tmax_alltime_record_x": sdata_all.tmax.max().values.item(),
"tmax_alltime_record_n": sdata_all.tmax.min().values.item(),
"tmin_alltime_record_x": sdata_all.tmin.max().values.item(),
"tmin_alltime_record_n": sdata_all.tmin.min().values.item(),
"tmed_alltime_record_x": sdata_all.tmed.max().values.item(),
"tmed_alltime_record_n": sdata_all.tmed.min().values.item(),
}
with open(f"{cfg.wrk_dir}/loc_stats.json", "w", encoding="utf-8") as f:
f.write(json.dumps(loc_stats, indent=2))
print(f"Elapsed time write json file: {time.time()-this_time}s")
this_time = time.time()
print(f"{bc.OKGREEN}Elapsed time TOTAL: {time.time()-start}s{bc.ENDC}")
###############################################################################
# __main__ scope
###############################################################################
if __name__ == "__main__":
raise SystemExit(main())
You should make python code to API then call api in React.
Call api may be Post/Get/Patch.
As for python api you can use Flask/Fast/Django or other framework.

How to serve a Python pickle file from a HTML page

I am trying to allow for downloading a Python pickle file from a Flask app through
import pickle
from flask import Flask, render_template_string
app = Flask(__name__)
template = """
<button onclick="download_file()" data-trigger-update-context="false">Download</button>
<script>
function download_file() {
mime_type = '{{ mime_type }}';
var blob = new Blob(['{{ file_content }}'], { type: mime_type });
var dlink = document.createElement('a');
dlink.download = 'pickle.pkl';
dlink.href = window.URL.createObjectURL(blob);
dlink.onclick = function (e) {
// revokeObjectURL needs a delay to work properly.
var that = this;
setTimeout(function () {
window.URL.revokeObjectURL(that.href);
}, 1500);
};
document.body.appendChild(dlink);
dlink.click();
dlink.remove();
}
</script>
"""
#app.route("/")
def download():
return render_template_string(
template,
file_content=pickle.dumps("text"),
mime_type="application/octet-stream",
)
While downloading the file works fine, the downloaded file itself seems corrupted as I get the following error while reading it
Python 3.7.6 | packaged by conda-forge | (default, Mar 23 2020, 23:03:20)
Type 'copyright', 'credits' or 'license' for more information
IPython 7.14.0 -- An enhanced Interactive Python. Type '?' for help.
In [1]: import pickle
In [2]: with open("pickle.pkl", "rb") as f:
...: pickle.load(f)
...:
---------------------------------------------------------------------------
UnpicklingError Traceback (most recent call last)
<ipython-input-2-b5282f4164d8> in <module>
1 with open("pickle.pkl", "rb") as f:
----> 2 pickle.load(f)
3
UnpicklingError: unpickling stack underflow
Any hint on the issue with the download script?
Thanks for your help.
Basically, you need to change just two things:
In the download() method, you need to convert the serialized bytes to a list of Integers.
Then, you need to change the JavaScript code to read this list of numbers.
So, your code should look like this:
import pickle
from flask import Flask, render_template_string
app = Flask(__name__)
template = """
<button onclick="download_file()" data-trigger-update-context="false">Download</button>
<script>
function download_file() {
let bytes_array = new Uint8Array({{file_content}}); //<--- add this
mime_type = '{{ mime_type }}';
var blob = new Blob([bytes_array], { type: mime_type }); //<-- change this
var dlink = document.createElement('a');
dlink.download = 'pickle.pkl';
dlink.href = window.URL.createObjectURL(blob);
dlink.onclick = function (e) {
// revokeObjectURL needs a delay to work properly.
var that = this;
setTimeout(function () {
window.URL.revokeObjectURL(that.href);
}, 1500);
};
document.body.appendChild(dlink);
dlink.click();
dlink.remove();
}
</script>
"""
#app.route("/")
def download():
return render_template_string(
template,
file_content=list(pickle.dumps("text")), # change this
mime_type="application/octet-stream",
)
if __name__ == '__main__':
app.run(debug = True)
Now, you can read the pickled file using pickle.load() just like so:
import pickle
with open("pickle.pkl", 'rb') as fin:
print(pickle.load(fin))
# prints: text

Node js Child Process Spawn runs whole python code every time I call

I have this code which connects Nodejs to Python script. The script contains ML models with Tensor flow backend and so on.., it basically gives a string output. I send an image URL from node js via.child process spawn to python and it gives back its recognised expression as a string. Basically I am doing facial recognition, coded in python but calling through Node js and send the string to response as JSON data(Rest API).
The problem I am facing is whenever I call spawn, it runs whole code of python and its taking so long as the python script has to load all modules if we start from the top and finally giving output.
Here is the python code
from gtts import gTTS
language = 'en'
#myobj = gTTS(text='Do you know the person? Yes or No', lang=language, slow=True)
#myobj.save("question1.mp3")
#myobj = gTTS(text='What is his or her name', lang=language, slow=True)
#myobj.save("question2.mp3")
import csv
import pandas as pd
import numpy as np
#with open('database.csv','w') as f:
# writer=csv.writer(f)
# writer.writerow(['Chinmay',embedded])
face_embeddings=np.array(pd.read_csv('database.csv',header=None))
face_names=np.array(pd.read_csv('database_names.csv',header=None))
from cv2 import cv2
import matplotlib.pyplot as plt
import matplotlib.patches as patches
from align import AlignDlib
import numpy as np
import matplotlib.pyplot as plt
from PIL import Image
import torch
import torch.nn as nn
import torch.nn.functional as F
import os
from torch.autograd import Variable
from model import create_model
import transforms as transforms
from skimage import io
from skimage.transform import resize
from models import *
import matplotlib.pyplot as plt
from keras.models import load_model
from keras.preprocessing.image import load_img, img_to_array
from util.model import CNNModel, generate_caption_beam_search
import os
from config import config
from pickle import load
import sys
cut_size = 44
transform_test = transforms.Compose([
transforms.TenCrop(cut_size),
transforms.Lambda(lambda crops: torch.stack([transforms.ToTensor()(crop) for crop in crops])),
])
class_names = ['Angry', 'Disgust', 'Fear', 'Happy', 'Sad', 'Surprise', 'Neutral']
final_text=''
nn4_small2_pretrained = create_model()
nn4_small2_pretrained.load_weights('weights/nn4.small2.v1.h5')
def rgb2gray(rgb):
return np.dot(rgb[...,:3], [0.299, 0.587, 0.114])
def load_image(path):
img = cv2.imread(path, 1)
# OpenCV loads images with color channels
# in BGR order. So we need to reverse them
return img[...,::-1]
def extract_features(filename, model, model_type):
if model_type == 'inceptionv3':
from keras.applications.inception_v3 import preprocess_input
target_size = (299, 299)
elif model_type == 'vgg16':
from keras.applications.vgg16 import preprocess_input
target_size = (224, 224)
# Loading and resizing image
image = load_img(filename, target_size=target_size)
# Convert the image pixels to a numpy array
image = img_to_array(image)
# Reshape data for the model
image = image.reshape((1, image.shape[0], image.shape[1], image.shape[2]))
# Prepare the image for the CNN Model model
image = preprocess_input(image)
# Pass image into model to get encoded features
features = model.predict(image, verbose=0)
return features
def getrecogstr( imgurl ):
# Path of Image
#image_file=imgurl
image_file = sys.argv[1]
# Initialize the OpenFace face alignment utility
alignment = AlignDlib('models/landmarks.dat')
# Load an image
jc_orig = load_image(image_file)
# Detect face and return bounding box -
bb = alignment.getAllFaceBoundingBoxes(jc_orig)
net = VGG('VGG19')
checkpoint = torch.load(os.path.join('FER2013_VGG19', 'PrivateTest_model.t7'),map_location='cpu')
net.load_state_dict(checkpoint['net'])
# Load the tokenizer
tokenizer_path = config['tokenizer_path']
tokenizer = load(open(tokenizer_path, 'rb'))
# Max sequence length (from training)
max_length = config['max_length']
caption_model = load_model('model.hdf5')
image_model = CNNModel(config['model_type'])
for i in bb:
# Transform image using specified face landmark indices and crop image to 96x96
jc_aligned = alignment.align(96, jc_orig, i, landmarkIndices=AlignDlib.OUTER_EYES_AND_NOSE)
location=(i.height()+i.width())/(jc_orig.shape[0]+jc_orig.shape[1])
# Finding the emotion of cropped image
gray = rgb2gray(jc_aligned)
gray = resize(gray, (48,48), mode='symmetric').astype(np.uint8)
img = gray[:, :, np.newaxis]
img = np.concatenate((img, img, img), axis=2)
img = Image.fromarray(img)
inputs = transform_test(img)
#net.cuda()
net.eval()
ncrops, c, h, w = np.shape(inputs)
inputs = inputs.view(-1, c, h, w)
#inputs = inputs.cuda()
inputs = Variable(inputs, volatile=True)
outputs = net(inputs)
outputs_avg = outputs.view(ncrops, -1).mean(0) # avg over crops
score = F.softmax(outputs_avg)
_, predicted = torch.max(outputs_avg.data, 0)
# Find the name of the person in the image
jc_aligned = (jc_aligned / 255.).astype(np.float32)
embeddings = nn4_small2_pretrained.predict(np.expand_dims(jc_aligned, axis=0))[0]
print("##")
print(embeddings)
matched_embeddings=1000
for j in range(len(face_embeddings)):
temp=np.sum(np.square(embeddings-face_embeddings[j]))
if (temp<=0.56 and temp <matched_embeddings):
matched_embeddings=np.sum(np.square(embeddings-face_embeddings[j]))
face_index=j
print(temp)
print('above')
if matched_embeddings!=1000:
face_name=face_names[face_index][0]
print("##known")
else:
face_name='Unknown'
print("##unknown")
#print("Unknown Person detected. Do you know this person yes or no ?")
#Play welcome1.mp3
#Play welcome2.mp3 if input is yes
final_text+= face_name+' expression is '+class_names[int(predicted.cpu().numpy())] + "."
print("##"+final_text)
sys.stdout.flush()
getrecogstr()
Here is the Node code
const express = require('express');
const app = express();
const bodyParser = require('body-parser');
const port = 1000;
const spawn = require("child_process").spawn;
app.use(bodyParser.json()); // application/json
app.use((req, res, next) => {
res.setHeader('Access-Control-Allow-Origin', '*');
res.setHeader('Access-Control-Allow-Methods', 'OPTIONS, GET, POST, PUT, PATCH, DELETE');
res.setHeader('Access-Control-Allow-Headers', 'Content-Type, Authorization');
next();
});
app.get('/test', (req, res, next) => {
const imgurl = req.query.imgurl;
var process = spawn('python', ["./final.py",
imgurl,
]);
process.stdout.on('data', function (data) {
const recog_str = data.toString().split('##')[3];
console.log(recog_str);
res.json(recog_str)
})
})
server.listen(port, () => {
console.log("Ok");
})
I just want to skip that part of loading modules every time. I know we have to run the modules for them to be in memory but it's taking so long. Can do like the python script is running all the time and we can send arguments from node js in the middle of that running and call a function which can return that string?
You could use a global variable and message communication between node and spawned python process.
I got the idea from this tutorial which is regarding the message queue, but the same method can be applied here.
app.js
const app = require('express')();
const uuid = require('uuid');
const spawn = require("child_process").spawn;
var py = spawn('python', ["./face.py"]);
var globalobj = {}
//whenever any data arrives, it will be stored in globalobj.
py.stdout.on('data', function (data) {
try {
const { id, msg } = JSON.parse(data.toString());
globalobj[id] = msg;
} catch (err) {
//If data chunk received is incomplete(child process sent large output) json parse fails.
}
});
const delay = () => new Promise(resolve => {
setTimeout(() => {
resolve();
}, 4000);
});
app.get('/test', async (req, res, next) => {
const url = req.query.imgurl;
const id = uuid.v4();
py.stdin.write(JSON.stringify({ id, url }) + "\n");
await delay();
//If no response has arrived from the child process, globalobj wont have id key.
if (globalobj[id] != undefined) {
res.send(globalobj[id]);
delete globalobj[id];
} else {
res.status(500).send('No response from child process');
}
});
app.listen(3000, 'localhost', () => {
console.log(`server started on port 3000`);
});
The downsides are the messages which get a response after the delay will be accumulated in the global object. Also the py.stdout.on('data', function(data){}) returns the data in stream, so if message is larger it will be split into chunks by nodejs. See this post
Reason for using \n when writing to child stdin can be found here.
main.py
import sys, json
while True:
stdin = sys.stdin.readline().replace("\n", "")
if stdin:
data = json.loads(stdin)
#do your computation here
print(json.dumps({'id': data['id'], 'msg': 'your message'}), flush=True)
stdin = None
When I quickly tested, it worked, but it may not work in all cases. Test this method well before using it.

Video is freezed while video streaming

I find the following code for streaming video over a socket in python2.7. When I run it, the video will be freeze at the beginning in the server-side (It shows the video in a web browser). I debugged the code and understood that in the streamer.py, the third while loop condition creates an infinite loop because of the condition while len(data) < msg_size: is always satisfied. In other words, len(data) is always less than msg_size.So, the streamer.py does not return the image to the server.py. Could anyone help me to solve this issue?
The server.py is:
from flask import Flask, render_template, Response
from streamer import Streamer
app = Flask(__name__)
def gen():
streamer = Streamer('localhost', 8089)
streamer.start()
while True:
if streamer.client_connected():
yield (b'--frame\r\n'b'Content-Type: image/jpeg\r\n\r\n' +
streamer.get_jpeg() + b'\r\n\r\n')
#app.route('/')
def index():
return render_template('index.html')
#app.route('/video_feed')
def video_feed():
return Response(gen(), mimetype='multipart/x-mixed-replace;
boundary=frame')
if __name__ == '__main__':
app.run(host='localhost', threaded=True)
The streamer.py is:
import threading
import socket
import struct
import StringIO
import json
import numpy
class Streamer (threading.Thread):
def __init__(self, hostname, port):
threading.Thread.__init__(self)
self.hostname = hostname
self.port = port
self.connected = False
self.jpeg = None
def run(self):
self.isRunning = True
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print 'Socket created'
s.bind((self.hostname, self.port))
print 'Socket bind complete'
data = ""
payload_size = struct.calcsize("L")
s.listen(10)
print 'Socket now listening'
while self.isRunning:
conn, addr = s.accept()
print 'while 1...'
while True:
data = conn.recv(4096)
print 'while 2...'
if data:
packed_msg_size = data[:payload_size]
data = data[payload_size:]
msg_size = struct.unpack("L", packed_msg_size)[0]
while len(data) < msg_size:# the infinite loop is here(my problem)!
data += conn.recv(4096)
print ("lenght of data is " , len(data) )
print ("message size is " , msg_size )
frame_data = data[:msg_size]
#frame_data = data[:len(data)]
memfile = StringIO.StringIO()
memfile.write(json.loads(frame_data).encode('latin-1'))
memfile.seek(0)
frame = numpy.load(memfile)
ret, jpeg = cv2.imencode('.jpg', frame)
self.jpeg = jpeg
self.connected = True
print 'recieving...'
else:
conn.close()
self.connected = False
print 'connected=false...'
break
self.connected = False
def stop(self):
self.isRunning = False
def client_connected(self):
return self.connected
def get_jpeg(self):
return self.jpeg.tobytes()
Client.py is:
import socket
import sys
import pickle
import struct
import StringIO
import json
import time
cap=cv2.VideoCapture(0)
clientsocket=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
clientsocket.connect(('localhost',8089))
while(cap.isOpened()):
ret,frame=cap.read()
memfile = StringIO.StringIO()
np.save(memfile, fravidme)
memfile.seek(0)
data = json.dumps(memfile.read().decode('latin-1'))
clientsocket.sendall(struct.pack("L", len(data))+data)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
cap.release()
I want to show the video captured by my laptop's camera on a client machine in the same network. I expect video stream but in the browser, I just watch an image and it does not update continuously.
As I analyzed this code I noticed that the default implementation for sending OpenCV frames over the network was not working. I decided to replace it with ZeroMQ implementation I have used before. You can check out the linked question for a deeper explanation of how the streaming works. I have neatly packaged it into classes, with unit tests and documentation as SmoothStream check it out too.
Coming back to the question, here is the working code.
client.py
import base64
import cv2
import zmq
context = zmq.Context()
footage_socket = context.socket(zmq.PUB)
footage_socket.connect('tcp://localhost:5555')
camera = cv2.VideoCapture(0) # init the camera
while True:
try:
grabbed, frame = camera.read() # grab the current frame
frame = cv2.resize(frame, (640, 480)) # resize the frame
encoded, buffer = cv2.imencode('.jpg', frame)
jpg_as_text = base64.b64encode(buffer)
footage_socket.send(jpg_as_text)
except KeyboardInterrupt:
camera.release()
cv2.destroyAllWindows()
break
server.py
from flask import Flask, render_template, Response
from streamer import Streamer
app = Flask(__name__)
def gen():
streamer = Streamer('*', 5555)
streamer.start()
while True:
if streamer.client_connected():
yield (b'--frame\r\n'b'Content-Type: image/jpeg\r\n\r\n' + streamer.get_jpeg() + b'\r\n\r\n')
#app.route('/')
def index():
return render_template('index.html')
#app.route('/video_feed')
def video_feed():
return Response(gen(), mimetype='multipart/x-mixed-replace; boundary=frame')
if __name__ == '__main__':
app.run(host='localhost', threaded=True)
streamer.py
import base64
import threading
import cv2
import numpy as np
import zmq
class Streamer(threading.Thread):
def __init__(self, hostname, port):
threading.Thread.__init__(self)
self.hostname = hostname
self.port = port
self.connected = False
self.jpeg = None
def run(self):
self.isRunning = True
context = zmq.Context()
footage_socket = context.socket(zmq.SUB)
footage_socket.bind('tcp://{}:{}'.format(self.hostname, self.port))
footage_socket.setsockopt_string(zmq.SUBSCRIBE, np.unicode(''))
while self.isRunning:
frame = footage_socket.recv_string()
img = base64.b64decode(frame)
npimg = np.fromstring(img, dtype=np.uint8)
source = cv2.imdecode(npimg, 1)
ret, jpeg = cv2.imencode('.jpg', source)
self.jpeg = jpeg
self.connected = True
self.connected = False
def stop(self):
self.isRunning = False
def client_connected(self):
return self.connected
def get_jpeg(self):
return self.jpeg.tobytes()
I understand that copy-pasting entire .py files are probably not the best way to post an answer here, but this is a complex question with a lot of moving parts and I honestly could not think of a better way to help the OP.

Splash (+scrapy) does not render web page correctly

Im' using Scrapy + Splash, I have problems downloading this page: http://new.abb.com/jobs/it/center#JobCountry=IT&JobCity=any&JobFunction=any&JobRole=any&JobText='http://new.abb.com/jobs/it/center#JobCountry=IT&JobCity=any&JobFunction=any&JobRole=any&JobText=
It seems that Splash cannot execute the javascript correctly.
Here is a stripped down, working, self contanied, version of my program (sorry if not stripped down at best)
# -*- coding: utf-8 -*- import scrapy from scrapy_splash import SplashRequest from scrapy.selector import Selector from scrapy.http import HtmlResponse import sys import io import os import base64
def saveFile(ss, fileNameExt, folderName):
f = open(folderName + '/' + fileNameExt, 'w')
f.write(ss)
f.close()
return fileNameExt
def savePng(png_bytes, fileNameExt, folderName):
f = open( folderName +'/' + fileNameExt, 'wb')
f.write(png_bytes)
f.close()
return fileNameExt
def savePageOriginalInFolder(response, folderName, chiave='pag1'):
fileName = "site.html"
testo = response.data[chiave].decode('utf8')
return saveFile(testo, fileName, folderName) def savePagePng(response, folderName, pngDataName):
fileName = 'site.png'
if hasattr(response, 'data'):
png_bytes = base64.b64decode(response.data[pngDataName])
return savePng(png_bytes, fileName, folderName)
class GenericoSpider(scrapy.Spider):
name = 'provaAbb'
def asSplashRequest(self, url, callback, id_elenco="no_id", id_sessione="no_id_sessione"):
return SplashRequest(
url = url,
endpoint='execute',
args={'lua_source': self.script, 'id_elenco': id_elenco, 'id_sessione': id_sessione},
callback=callback,
)
outDir = name # prendo in nome della cartella dal nome dello spider
db_name = ""
def start_requests(self):
sito = 'http://new.abb.com/jobs/it/center#JobCountry=IT&JobCity=any&JobFunction=any&JobRole=any&JobText='
yield self.asSplashRequest(sito, self.parse_list, 'id_mio_elenco')
script = """
function main(splash)
local url = splash.args.url
splash:set_viewport_size(1280, 2500)
splash:init_cookies(splash.args.cookies)
assert(splash:go(url))
assert(splash:wait(10))
return {
url = splash:url(),
pag1 = splash:html(),
png1 = splash:png(),
id_elenco = splash.args.id_elenco,
id_sessione = splash.args.id_sessione,
cookies = splash:get_cookies(),
tt = splash.args
}
end
"""
def parse_list(self, response):
for ss in response.data:
if len(ss) >= 4:
if ss[0:3] == 'pag':
fileName = savePageOriginalInFolder(response, self.outDir, ss)
elif ss[0:3] == 'png':
fileName = savePagePng(response, self.outDir,ss)
A part of the settings.py
DOWNLOADER_MIDDLEWARES = {
'scrapy_splash.SplashCookiesMiddleware': 723,
'scrapy_splash.SplashMiddleware': 725,
'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware': 810, }
SPIDER_MIDDLEWARES = {
'scrapy_splash.SplashDeduplicateArgsMiddleware': 100, }
DUPEFILTER_CLASS = 'scrapy_splash.SplashAwareDupeFilter'
HTTPCACHE_STORAGE = 'scrapy_splash.SplashAwareFSCacheStorage'
Result, as you can see there is the spinner in the list area and page numbers are not loaded. (augmenting wait time in lua did not solve the problem)

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