Telegram bot price

How to build a telegram bot which retrieve price in real time from a DEX on python

Requirements

Python libraries

You will need to install web3 and telegram-bot python libraries

pip install web3 python-telegram-bot --upgrade

Creating bot on telegram

You will first need to contact BotFather on telegram : https://t.me/botfather and follow the instructions Don't forget to not your token for later !

Coding the bot

Basic configuration

Now let's start coding our bot : we need to import web and some telegram-bot modules and some basic configuration.

priceBot.py

from web3 import Web3
from telegram.ext import Updater
from telegram.ext import CommandHandler
import logging
import json

# Enable logging
logging.basicConfig(
    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s', level=logging.INFO
)
logger = logging.getLogger(__name__)

#Web3
w3 = Web3(Web3.HTTPProvider('http://127.0.0.1:9650/ext/bc/C/rpc'))

#Telegram
updater = Updater(token=YOUR_TOKEN, use_context=True)
dispatcher = updater.dispatcher

#Basic bot command
def start(update, context):
    pass

#We associate the keyword start with the start command and add it to the dispatcher
start_handler = CommandHandler('start', start)
dispatcher.add_handler(start_handler)
#Starting listening to commands
updater.start_polling()

Some variables we need

We will need a few variables like the factories addresses, and some ABIs.

ERC20.json

[{"type":"event","name":"Approval","inputs":[{"type":"address","name":"src","internalType":"address","indexed":true},{"type":"address","name":"guy","internalType":"address","indexed":true},{"type":"uint256","name":"wad","internalType":"uint256","indexed":false}],"anonymous":false},{"type":"event","name":"Deposit","inputs":[{"type":"address","name":"dst","internalType":"address","indexed":true},{"type":"uint256","name":"wad","internalType":"uint256","indexed":false}],"anonymous":false},{"type":"event","name":"Transfer","inputs":[{"type":"address","name":"src","internalType":"address","indexed":true},{"type":"address","name":"dst","internalType":"address","indexed":true},{"type":"uint256","name":"wad","internalType":"uint256","indexed":false}],"anonymous":false},{"type":"event","name":"Withdrawal","inputs":[{"type":"address","name":"src","internalType":"address","indexed":true},{"type":"uint256","name":"wad","internalType":"uint256","indexed":false}],"anonymous":false},{"type":"fallback","stateMutability":"payable","payable":true},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"uint256","name":"","internalType":"uint256"}],"name":"allowance","inputs":[{"type":"address","name":"","internalType":"address"},{"type":"address","name":"","internalType":"address"}],"constant":true},{"type":"function","stateMutability":"nonpayable","payable":false,"outputs":[{"type":"bool","name":"","internalType":"bool"}],"name":"approve","inputs":[{"type":"address","name":"guy","internalType":"address"},{"type":"uint256","name":"wad","internalType":"uint256"}],"constant":false},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"uint256","name":"","internalType":"uint256"}],"name":"balanceOf","inputs":[{"type":"address","name":"","internalType":"address"}],"constant":true},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"uint8","name":"","internalType":"uint8"}],"name":"decimals","inputs":[],"constant":true},{"type":"function","stateMutability":"payable","payable":true,"outputs":[],"name":"deposit","inputs":[],"constant":false},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"string","name":"","internalType":"string"}],"name":"name","inputs":[],"constant":true},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"string","name":"","internalType":"string"}],"name":"symbol","inputs":[],"constant":true},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"uint256","name":"","internalType":"uint256"}],"name":"totalSupply","inputs":[],"constant":true},{"type":"function","stateMutability":"nonpayable","payable":false,"outputs":[{"type":"bool","name":"","internalType":"bool"}],"name":"transfer","inputs":[{"type":"address","name":"dst","internalType":"address"},{"type":"uint256","name":"wad","internalType":"uint256"}],"constant":false},{"type":"function","stateMutability":"nonpayable","payable":false,"outputs":[{"type":"bool","name":"","internalType":"bool"}],"name":"transferFrom","inputs":[{"type":"address","name":"src","internalType":"address"},{"type":"address","name":"dst","internalType":"address"},{"type":"uint256","name":"wad","internalType":"uint256"}],"constant":false},{"type":"function","stateMutability":"nonpayable","payable":false,"outputs":[],"name":"withdraw","inputs":[{"type":"uint256","name":"wad","internalType":"uint256"}],"constant":false}]

Factory.json

[{"type":"constructor","stateMutability":"nonpayable","payable":false,"inputs":[{"type":"address","name":"_feeToSetter","internalType":"address"}]},{"type":"event","name":"PairCreated","inputs":[{"type":"address","name":"token0","internalType":"address","indexed":true},{"type":"address","name":"token1","internalType":"address","indexed":true},{"type":"address","name":"pair","internalType":"address","indexed":false},{"type":"uint256","name":"","internalType":"uint256","indexed":false}],"anonymous":false},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"address","name":"","internalType":"address"}],"name":"allPairs","inputs":[{"type":"uint256","name":"","internalType":"uint256"}],"constant":true},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"uint256","name":"","internalType":"uint256"}],"name":"allPairsLength","inputs":[],"constant":true},{"type":"function","stateMutability":"nonpayable","payable":false,"outputs":[{"type":"address","name":"pair","internalType":"address"}],"name":"createPair","inputs":[{"type":"address","name":"tokenA","internalType":"address"},{"type":"address","name":"tokenB","internalType":"address"}],"constant":false},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"address","name":"","internalType":"address"}],"name":"feeTo","inputs":[],"constant":true},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"address","name":"","internalType":"address"}],"name":"feeToSetter","inputs":[],"constant":true},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"address","name":"","internalType":"address"}],"name":"getPair","inputs":[{"type":"address","name":"","internalType":"address"},{"type":"address","name":"","internalType":"address"}],"constant":true},{"type":"function","stateMutability":"nonpayable","payable":false,"outputs":[],"name":"setFeeTo","inputs":[{"type":"address","name":"_feeTo","internalType":"address"}],"constant":false},{"type":"function","stateMutability":"nonpayable","payable":false,"outputs":[],"name":"setFeeToSetter","inputs":[{"type":"address","name":"_feeToSetter","internalType":"address"}],"constant":false}]

Pool.json

[{"type":"constructor","stateMutability":"nonpayable","payable":false,"inputs":[]},{"type":"event","name":"Approval","inputs":[{"type":"address","name":"owner","internalType":"address","indexed":true},{"type":"address","name":"spender","internalType":"address","indexed":true},{"type":"uint256","name":"value","internalType":"uint256","indexed":false}],"anonymous":false},{"type":"event","name":"Burn","inputs":[{"type":"address","name":"sender","internalType":"address","indexed":true},{"type":"uint256","name":"amount0","internalType":"uint256","indexed":false},{"type":"uint256","name":"amount1","internalType":"uint256","indexed":false},{"type":"address","name":"to","internalType":"address","indexed":true}],"anonymous":false},{"type":"event","name":"Mint","inputs":[{"type":"address","name":"sender","internalType":"address","indexed":true},{"type":"uint256","name":"amount0","internalType":"uint256","indexed":false},{"type":"uint256","name":"amount1","internalType":"uint256","indexed":false}],"anonymous":false},{"type":"event","name":"Swap","inputs":[{"type":"address","name":"sender","internalType":"address","indexed":true},{"type":"uint256","name":"amount0In","internalType":"uint256","indexed":false},{"type":"uint256","name":"amount1In","internalType":"uint256","indexed":false},{"type":"uint256","name":"amount0Out","internalType":"uint256","indexed":false},{"type":"uint256","name":"amount1Out","internalType":"uint256","indexed":false},{"type":"address","name":"to","internalType":"address","indexed":true}],"anonymous":false},{"type":"event","name":"Sync","inputs":[{"type":"uint112","name":"reserve0","internalType":"uint112","indexed":false},{"type":"uint112","name":"reserve1","internalType":"uint112","indexed":false}],"anonymous":false},{"type":"event","name":"Transfer","inputs":[{"type":"address","name":"from","internalType":"address","indexed":true},{"type":"address","name":"to","internalType":"address","indexed":true},{"type":"uint256","name":"value","internalType":"uint256","indexed":false}],"anonymous":false},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"bytes32","name":"","internalType":"bytes32"}],"name":"DOMAIN_SEPARATOR","inputs":[],"constant":true},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"uint256","name":"","internalType":"uint256"}],"name":"MINIMUM_LIQUIDITY","inputs":[],"constant":true},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"bytes32","name":"","internalType":"bytes32"}],"name":"PERMIT_TYPEHASH","inputs":[],"constant":true},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"uint256","name":"","internalType":"uint256"}],"name":"allowance","inputs":[{"type":"address","name":"","internalType":"address"},{"type":"address","name":"","internalType":"address"}],"constant":true},{"type":"function","stateMutability":"nonpayable","payable":false,"outputs":[{"type":"bool","name":"","internalType":"bool"}],"name":"approve","inputs":[{"type":"address","name":"spender","internalType":"address"},{"type":"uint256","name":"value","internalType":"uint256"}],"constant":false},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"uint256","name":"","internalType":"uint256"}],"name":"balanceOf","inputs":[{"type":"address","name":"","internalType":"address"}],"constant":true},{"type":"function","stateMutability":"nonpayable","payable":false,"outputs":[{"type":"uint256","name":"amount0","internalType":"uint256"},{"type":"uint256","name":"amount1","internalType":"uint256"}],"name":"burn","inputs":[{"type":"address","name":"to","internalType":"address"}],"constant":false},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"uint8","name":"","internalType":"uint8"}],"name":"decimals","inputs":[],"constant":true},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"address","name":"","internalType":"address"}],"name":"factory","inputs":[],"constant":true},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"uint112","name":"_reserve0","internalType":"uint112"},{"type":"uint112","name":"_reserve1","internalType":"uint112"},{"type":"uint32","name":"_blockTimestampLast","internalType":"uint32"}],"name":"getReserves","inputs":[],"constant":true},{"type":"function","stateMutability":"nonpayable","payable":false,"outputs":[],"name":"initialize","inputs":[{"type":"address","name":"_token0","internalType":"address"},{"type":"address","name":"_token1","internalType":"address"}],"constant":false},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"uint256","name":"","internalType":"uint256"}],"name":"kLast","inputs":[],"constant":true},{"type":"function","stateMutability":"nonpayable","payable":false,"outputs":[{"type":"uint256","name":"liquidity","internalType":"uint256"}],"name":"mint","inputs":[{"type":"address","name":"to","internalType":"address"}],"constant":false},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"string","name":"","internalType":"string"}],"name":"name","inputs":[],"constant":true},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"uint256","name":"","internalType":"uint256"}],"name":"nonces","inputs":[{"type":"address","name":"","internalType":"address"}],"constant":true},{"type":"function","stateMutability":"nonpayable","payable":false,"outputs":[],"name":"permit","inputs":[{"type":"address","name":"owner","internalType":"address"},{"type":"address","name":"spender","internalType":"address"},{"type":"uint256","name":"value","internalType":"uint256"},{"type":"uint256","name":"deadline","internalType":"uint256"},{"type":"uint8","name":"v","internalType":"uint8"},{"type":"bytes32","name":"r","internalType":"bytes32"},{"type":"bytes32","name":"s","internalType":"bytes32"}],"constant":false},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"uint256","name":"","internalType":"uint256"}],"name":"price0CumulativeLast","inputs":[],"constant":true},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"uint256","name":"","internalType":"uint256"}],"name":"price1CumulativeLast","inputs":[],"constant":true},{"type":"function","stateMutability":"nonpayable","payable":false,"outputs":[],"name":"skim","inputs":[{"type":"address","name":"to","internalType":"address"}],"constant":false},{"type":"function","stateMutability":"nonpayable","payable":false,"outputs":[],"name":"swap","inputs":[{"type":"uint256","name":"amount0Out","internalType":"uint256"},{"type":"uint256","name":"amount1Out","internalType":"uint256"},{"type":"address","name":"to","internalType":"address"},{"type":"bytes","name":"data","internalType":"bytes"}],"constant":false},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"string","name":"","internalType":"string"}],"name":"symbol","inputs":[],"constant":true},{"type":"function","stateMutability":"nonpayable","payable":false,"outputs":[],"name":"sync","inputs":[],"constant":false},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"address","name":"","internalType":"address"}],"name":"token0","inputs":[],"constant":true},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"address","name":"","internalType":"address"}],"name":"token1","inputs":[],"constant":true},{"type":"function","stateMutability":"view","payable":false,"outputs":[{"type":"uint256","name":"","internalType":"uint256"}],"name":"totalSupply","inputs":[],"constant":true},{"type":"function","stateMutability":"nonpayable","payable":false,"outputs":[{"type":"bool","name":"","internalType":"bool"}],"name":"transfer","inputs":[{"type":"address","name":"to","internalType":"address"},{"type":"uint256","name":"value","internalType":"uint256"}],"constant":false},{"type":"function","stateMutability":"nonpayable","payable":false,"outputs":[{"type":"bool","name":"","internalType":"bool"}],"name":"transferFrom","inputs":[{"type":"address","name":"from","internalType":"address"},{"type":"address","name":"to","internalType":"address"},{"type":"uint256","name":"value","internalType":"uint256"}],"constant":false}]

with open("Factory.json") as factoryFile:
    factoryABI = json.load(factoryFile)
with open("Pool.json") as poolFile :
    poolABI = json.load(poolFile )
with open("ERC20.json") as erc20File:
    ERC20ABI = json.load(erc20File)

dexesAddresses = [
    ["Yetiswap",  "0x58C8CD291Fa36130119E6dEb9E520fbb6AcA1c3a"],
    ["Pangolin", "0xefa94DE7a4656D787667C749f7E1223D71E9FD88"],
    ["Complus", "0x5C02e78A3969D0E64aa2CFA765ACc1d671914aC0"],
    ["SushiSwap", "0xc35DADB65012eC5796536bD9864eD8773aBc74C4"],
    ["Zero", "0x2Ef422F30cdb7c5F1f7267AB5CF567A88974b308"],
    ["Elk", "0x091d35d7f63487909c863001ddca481c6de47091"],
    ["PandaSwap", "0xc7e37A28bB17EdB59E99d5485Dc8c51BC87aE699"]
]

Initializing DEXs and pools

Next we need to retrieve pools informations from DEXs in order to do so we will call the factory contract of each DEX and list all pairs available.

We will first define a Dex, Token and Pair class.

class Dex():
    def __init__(self, factoryContract, name):
        self.factoryContract = factoryContract
        self.name = name
        self.pairs = list()

class Token():
    def __init__(self, contract, address, symbol, decimals, name):
        self.contract = contract
        self.address = address
        self.symbol = symbol
        self.decimals = decimals
        self.name = name

We also define a function to update the liquidity on a pair which will be useful later.

class Pair():
    def __init__(self, contract, token0, token1):
        self.contract = contract
        self.token0 = token0
        self.token1 = token1
        self.token0Liquidity = 0
        self.token1Liquidity = 0
        
    def updateLiquidity(self):
        reserves = self.contract.functions.getReserves().call()
        self.token0Liquidity = reserves[0]
        self.token1Liquidity = reserves[1]

Once we have done that we can populate a list of dex with all its pairs.

dexes = list()

for dex in dexesAddresses :
    dexName = dex[0]
    dexAddress = dex[1]
    #We instantiate the dex contract
    dexContract = w3.eth.contract(address=w3.toCheksumAddress(dexAddress), abi=factoryABI)
    #We instantiate a new dex object and add it to our list
    newDex = Dex(dexContract, dexName)
    newDex.updatePairs()
    dexes.append(newDex)

Nice we now have our list of DEXs but there are no pairs associated with them so we need to write a function to retrieve them.

class Dex():
    def __init__(self, factoryContract, name):
        self.factoryContract = factoryContract
        self.name = name
        self.pairs = list()
    
    def updatePairs(self):
        #We get the number of pairs on this dex
        pairsOnDex = self.factoryContract.functions.allPairsLength().call()
        #And we want to retrieve pairs we don't know yet
        for i in range(len(self.pairs), pairsOnDex) :
            #We ask what is the pair i and it returns its address
            newPairAddress = self.factoryContract.functions.allPairs(i).call()
            #Now we instantiate a pair contract for this pair
            newPairContract = w3.eth.contract(address=newPairAddress, abi=poolABI)
            token0Address = newPairContract.functions.token0().call()
            token1Address = newPairContract.functions.token1().call()
            #Now we instantiate a contract for each one
            newToken0Contract = w3.eth.contract(address=token0Address, abi=ERC20ABI)
            newToken1Contract = w3.eth.contract(address=token1Address, abi=ERC20ABI)
            #And a Token object
            newToken0Symbol = newToken0Contract.functions.symbol().call()
            newToken0Decimals = newToken0Contract.functions.decimals().call()
            newToken0Name = newToken0Contract.functions.name().call()
            newToken0 = Token(newToken0Contract, token0Address, newToken0Symbol, newToken0Decimals, newToken0Name)
            
            newToken1Symbol = newToken1Contract.functions.symbol().call()
            newToken1Decimals = newToken1Contract.functions.decimals().call()
            newToken1Name = newToken1Contract.functions.name().call()
            newToken1 = Token(newToken1Contract, token1Address, newToken1Symbol, newToken1Decimals, newToken1Name)
            
            #We can create the Pair object
            newPair = Pair(newPairContract, newToken0, newToken1)
            #And we update its liquidity
            #newPair.updateLiquidity()
            self.pairs.append(newPair)

That's good but there is still a problem we create a new token for each pair even if we alredy know it. To avoid this we will create a dict containing all tokens we already know about.

tokensWeKnow = dict()

And we update our code.

for i in range(len(self.pairs), pairsOnDex) :
    #We ask what is the pair i and it returns its address
    newPairAddress = self.factoryContract.functions.allPairs(i).call()
    #Now we instantiate a pair contract for this pair
    newPairContract = w3.eth.contract(address=newPairAddress, abi=poolABI)
    token0Address = newPairContract.functions.token0().call()
    token1Address = newPairContract.functions.token1().call()
    #We check if we already know it
    if token0Address in tokensWeKnow :
        newtoken0 = tokensWeKnow[token0Address]
    else :
        newToken0Contract = w3.eth.contract(address=token0Address, abi=ERC20ABI)
        #And a Token object
        newToken0Symbol = newToken0Contract.functions.symbol().call()
        newToken0Decimals = newToken0Contract.functions.decimals().call()
        newToken0Name = newToken0Contract.functions.name().call()
        newToken0 = Token(newToken0Contract, token0Address, newToken0Symbol, newToken0Decimals, newToken0Name)
    if token1Address in tokensWeKnow :
        newtoken1 = tokensWeKnow[token1Address]
    else :
        newToken1Contract = w3.eth.contract(address=token1Address, abi=ERC20ABI)
        newToken1Symbol = newToken1Contract.functions.symbol().call()
        newToken1Decimals = newToken1Contract.functions.decimals().call()
        newToken1Name = newToken1Contract.functions.name().call()
        newToken1 = Token(newToken1Contract, token1Address, newToken1Symbol, newToken1Decimals, newToken1Name)

    #We can create the Pair object
    newPair = Pair(newPairContract, newToken0, newToken1)
    #And we update its liquidity
    newPair.updateLiquidity()
    self.pairs.append(newPair)

Calculate price

Now we need to know from which pair we want to calculate the price from, we will try all dexes and keep one with the highest avax (or usdt) liquidity. For each token we will calculate 2 prices : one in AVAX on in USDT.

def findPair(tokenSymbol, otherSymbol, dexes):
    #We must care if there is multiple pair with same Symbol
    liquidity = 0
    for dex in dexes :
        for pair in dex.pairs :
            if pair.token0.symbol == tokenSymbol and pair.token1.symbol == otherSymbol or pair.token1.symbol == tokenSymbol and pair.token0.symbol == otherSymbol :
                if pair.token0.symbol == tokenSymbol and pair.token1Liquidity > liquidity :
                    currentPair = pair
                    liquidity = pair.token1Liquidity
                    currentDex = dex
                elif pair.token1.symbol == tokenSymbol and pair.token0Liquidity > liquidity :
                    currentPair = pair
                    liquidity = pair.token0Liquidity
                    currentDex = dex
    try :
        return currentPair, currentDex
    except :
        return None, None

def findAVAXPair(tokenSymbol, dex):
    return findPair(tokenSymbol, "WAVAX", dex)

def findUSDTPair(tokenSymbol, dex):
    return findPair(tokenSymbol, "USDT", dex)

Once we've done that we need to calculate the price.

def price(tokenSymbol, pair):
    if pair.token0.symbol == tokenSymbol :
        return (pair.token1Liquidity / 10**pair.token1.decimals) / (pair.token0Liquidity / 10**pair.token0.decimals)
    else :
        return (pair.token0Liquidity / 10**pair.token0.decimals) / (pair.token1Liquidity / 10**pair.token1.decimals)

Telegram function

Let's code the telegram function now. If we find a avax or usdt pair for this token we send a message with the current highest liquid price. (we transform avax in wavax since pairs are in wavax)

def telegramPrice(update, context):
    tokenSymbol = update.message.text[7:]
    tokenSymbol = tokenSymbol.upper()
    if tokenSymbol == "AVAX" :
        tokenSymbol = "WAVAX"
    logger.info("Looking price for %s", tokenSymbol)
    pairAVAX, dex1 = findAVAXPair(tokenSymbol, dexes)
    pairUSDT, dex2 = findUSDTPair(tokenSymbol, dexes)
    if pairAVAX != None :
        #We update the liquidity
        pairAVAX.updateLiquidity()
        tokenPriceAVAX = price(tokenSymbol, pairAVAX)
        context.bot.send_message(chat_id=update.effective_chat.id, text="Price : {:,.4f}{}/{} (on {})".format(tokenPriceAVAX, "AVAX", tokenSymbol, dex1.name))
    if pairUSDT != None :
        pairUSDT.updateLiquidity()
        tokenPriceUSDT = price(tokenSymbol, pairUSDT)
        context.bot.send_message(chat_id=update.effective_chat.id, text="Price : {:,.4f}{}/{} (on {})".format(tokenPriceUSDT, "USDT", tokenSymbol, dex2.name))

telegramPriceHandler = CommandHandler('price', telegramPrice)
dispatcher.add_handler(telegramPriceHandler)

Final code

telegramPriceBot.py

from web3 import Web3
from telegram.ext import Updater
from telegram.ext import CommandHandler
import logging
import json

# Enable logging
logging.basicConfig(
    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s', level=logging.INFO
)
logger = logging.getLogger(__name__)

#Web3
w3 = Web3(Web3.HTTPProvider('http://127.0.0.1:9650/ext/bc/C/rpc'))

class Dex():
    def __init__(self, factoryContract, name):
        self.factoryContract = factoryContract
        self.name = name
        self.pairs = list()
    
    def updatePairs(self):
        #We get the number of pairs on this dex
        pairsOnDex = self.factoryContract.functions.allPairsLength().call()
        #And we want to retrieve pairs we don't know yet
        for i in range(len(self.pairs), pairsOnDex) :
            #We ask what is the pair i and it returns its address
            newPairAddress = self.factoryContract.functions.allPairs(i).call()
            #Now we instantiate a pair contract for this pair
            newPairContract = w3.eth.contract(address=newPairAddress, abi=poolABI)
            token0Address = newPairContract.functions.token0().call()
            token1Address = newPairContract.functions.token1().call()
            #We check if we already know it
            if token0Address in tokensWeKnow :
                newToken0 = tokensWeKnow[token0Address]
            else :
                newToken0Contract = w3.eth.contract(address=token0Address, abi=ERC20ABI)
                #And a Token object
                newToken0Symbol = newToken0Contract.functions.symbol().call()
                newToken0Decimals = newToken0Contract.functions.decimals().call()
                newToken0Name = newToken0Contract.functions.name().call()
                newToken0 = Token(newToken0Contract, token0Address, newToken0Symbol, newToken0Decimals, newToken0Name)
                tokensWeKnow[token0Address] = newToken0
            if token1Address in tokensWeKnow :
                newToken1 = tokensWeKnow[token1Address]
            else :
                newToken1Contract = w3.eth.contract(address=token1Address, abi=ERC20ABI)
                newToken1Symbol = newToken1Contract.functions.symbol().call()
                newToken1Decimals = newToken1Contract.functions.decimals().call()
                newToken1Name = newToken1Contract.functions.name().call()
                newToken1 = Token(newToken1Contract, token1Address, newToken1Symbol, newToken1Decimals, newToken1Name)
                tokensWeKnow[token1Address] = newToken1

            #We can create the Pair object
            newPair = Pair(newPairContract, newToken0, newToken1)
            #And we update its liquidity
            newPair.updateLiquidity()
            self.pairs.append(newPair)

class Token():
    def __init__(self, contract, address, symbol, decimals, name):
        self.contract = contract
        self.address = address
        self.symbol = symbol
        self.decimals = decimals
        self.name = name

class Pair():
    def __init__(self, contract, token0, token1):
        self.contract = contract
        self.token0 = token0
        self.token1 = token1
        self.token0Liquidity = 0
        self.token1Liquidity = 0
        
    def updateLiquidity(self):
        reserves = self.contract.functions.getReserves().call()
        self.token0Liquidity = reserves[0]
        self.token1Liquidity = reserves[1]

def findPair(tokenSymbol, otherSymbol, dexes):
    #We must care if there is multiple pair with same Symbol
    liquidity = 0
    for dex in dexes :
        for pair in dex.pairs :
            if pair.token0.symbol == tokenSymbol and pair.token1.symbol == otherSymbol or pair.token1.symbol == tokenSymbol and pair.token0.symbol == otherSymbol :
                if pair.token0.symbol == tokenSymbol and pair.token1Liquidity > liquidity :
                    currentPair = pair
                    liquidity = pair.token1Liquidity
                    currentDex = dex
                elif pair.token1.symbol == tokenSymbol and pair.token0Liquidity > liquidity :
                    currentPair = pair
                    liquidity = pair.token0Liquidity
                    currentDex = dex
    try :
        return currentPair, currentDex
    except :
        return None, None

def findAVAXPair(tokenSymbol, dex):
    return findPair(tokenSymbol, "WAVAX", dex)

def findUSDTPair(tokenSymbol, dex):
    return findPair(tokenSymbol, "USDT", dex)

def price(tokenSymbol, pair):
    if pair.token0.symbol == tokenSymbol :
        return (pair.token1Liquidity / 10**pair.token1.decimals) / (pair.token0Liquidity / 10**pair.token0.decimals)
    else :
        return (pair.token0Liquidity / 10**pair.token0.decimals) / (pair.token1Liquidity / 10**pair.token1.decimals)

#Telegram
updater = Updater(token="YOUR_TOKEN", use_context=True)
dispatcher = updater.dispatcher

with open("Factory.json") as factoryFile:
    factoryABI = json.load(factoryFile)
with open("Pool.json") as poolFile :
    poolABI = json.load(poolFile )
with open("ERC20.json") as erc20File:
    ERC20ABI = json.load(erc20File)

dexesAddresses = [
    ["Yetiswap",  "0x58C8CD291Fa36130119E6dEb9E520fbb6AcA1c3a"],
    ["Pangolin", "0xefa94DE7a4656D787667C749f7E1223D71E9FD88"],
    ["Complus", "0x5C02e78A3969D0E64aa2CFA765ACc1d671914aC0"],
    ["SushiSwap", "0xc35DADB65012eC5796536bD9864eD8773aBc74C4"],
    ["Zero", "0x2Ef422F30cdb7c5F1f7267AB5CF567A88974b308"],
    ["Elk", "0x091d35d7f63487909c863001ddca481c6de47091"],
    ["PandaSwap", "0xc7e37A28bB17EdB59E99d5485Dc8c51BC87aE699"]
]
tokensWeKnow = dict()
dexes = list()

for dex in dexesAddresses :
    dexName = dex[0]
    dexAddress = dex[1]
    #We instantiate the dex contract
    dexContract = w3.eth.contract(address=w3.toChecksumAddress(dexAddress), abi=factoryABI)
    #We instantiate a new dex object and add it to our list
    newDex = Dex(dexContract, dexName)
    newDex.updatePairs()
    dexes.append(newDex)


def telegramPrice(update, context):
    tokenSymbol = update.message.text[7:]
    tokenSymbol = tokenSymbol.upper()
    if tokenSymbol == "AVAX" :
        tokenSymbol = "WAVAX"
    pairAVAX, dex1 = findAVAXPair(tokenSymbol, dexes)
    pairUSDT, dex2 = findUSDTPair(tokenSymbol, dexes)
    if pairAVAX != None :
        #We update the liquidity
        pairAVAX.updateLiquidity()
        tokenPriceAVAX = price(tokenSymbol, pairAVAX)
        context.bot.send_message(chat_id=update.effective_chat.id, text="Price : {:,.4f}{}/{} (on {})".format(tokenPriceAVAX, "AVAX", tokenSymbol, dex1.name))
    if pairUSDT != None :
        pairUSDT.updateLiquidity()
        tokenPriceUSDT = price(tokenSymbol, pairUSDT)
        context.bot.send_message(chat_id=update.effective_chat.id, text="Price : {:,.4f}{}/{} (on {})".format(tokenPriceUSDT, "USDT", tokenSymbol, dex2.name))

telegramPriceHandler = CommandHandler('price', telegramPrice)
dispatcher.add_handler(telegramPriceHandler)
#Starting listening to commands
updater.start_polling()

What's next ?

There is still some problems : if someone create a new pair on a DEX we can't check its price without rebooting the bot, we could fix this easily by adding a command doing this / since we only update liquidity on request and we do after we found which pair as highest liquidity this pair can't change, here as well we could do a command to update this or a timer to do this automatically, we could improve aswell the output format for super high or super low price coins.