PairDetails

Documentation for eth_defi.uniswap_v2.pair.PairDetails Python class.

class PairDetails[source]

Uniswap v2 trading pair info.

An example usage how to get the latest price of a pair on PancakeSwap. The PairDetails class will do an automatic conversion of prices to human-readable, decimal format:

from web3 import Web3, HTTPProvider

from eth_defi.chain import install_chain_middleware
from eth_defi.uniswap_v2.pair import fetch_pair_details

web3 = Web3(HTTPProvider("https://bsc-dataseed.bnbchain.org"))

print(f"Connected to chain {web3.eth.chain_id}")

# BNB Chain does its own things
install_chain_middleware(web3)

# Find pair addresses on TradingStrategy.ai
# https://tradingstrategy.ai/trading-view/binance/pancakeswap-v2/bnb-busd
pair_address = "0x58f876857a02d6762e0101bb5c46a8c1ed44dc16"
wbnb = "0xbb4CdB9CBd36B01bD1cBaEBF2De08d9173bc095c"
busd = "0xe9e7CEA3DedcA5984780Bafc599bD69ADd087D56"

# PancakeSwap has this low level encoded token0/token1 as BNB/BUSD
# in human-readable token order
# and we do not need to swap around
reverse_token_order = False

pair = fetch_pair_details(
    web3,
    pair_address,
    reverse_token_order,
)

assert pair.token0.address == wbnb
assert pair.token1.address == busd

price = pair.get_current_mid_price()

# Assume 1 BUSD = 1 USD
print(f"The current price of PancakeSwap BNB/BUSD is {price:.4f} USD")

Attributes summary

contract

Pool contract

token0

One pair of tokens

token1

One pair of tokens

reverse_token_order

Store the human readable token order on this data.

address

Get pair contract address

checksum_free_address

Get pair contract address, all lowercase.

Methods summary

__init__(contract, token0, token1[, ...])

convert_price_to_human(reserve0, reserve1[, ...])

Convert the price obtained through Sync event

get_base_token()

Get human-ordered base token.

get_current_mid_price()

Return the price in this pool.

get_quote_token()

Get human-ordered quote token.
contract: web3.contract.contract.Contract

Pool contract

https://docs.uniswap.org/contracts/v2/reference/smart-contracts/pair#getreserves

token0: eth_defi.token.TokenDetails

One pair of tokens

token1: eth_defi.token.TokenDetails

One pair of tokens

reverse_token_order: Optional[bool]

Store the human readable token order on this data.

If false then pair reads as token0 symbol (WETH) - token1 symbol (USDC).

If true then pair reads as token1 symbol (USDC) - token0 symbol (WETH).

property address: eth_typing.evm.HexAddress

Get pair contract address

property checksum_free_address: str

Get pair contract address, all lowercase.

get_base_token()[source]

Get human-ordered base token.

get_quote_token()[source]

Get human-ordered quote token.

convert_price_to_human(reserve0, reserve1, reverse_token_order=None)[source]

Convert the price obtained through Sync event

Parameters

  • reverse_token_order –

    Decide token order for human (base, quote token) order. If set, assume quote token is token0.

    IF set to None, use value from the data.

  • reserve0 (int) –

  • reserve1 (int) –

get_current_mid_price()[source]

Return the price in this pool.

Calls getReserves() over JSON-RPC and calculate the current price basede on the pair reserves.

See https://docs.uniswap.org/contracts/v2/reference/smart-contracts/pair#getreserves

Returns

Quote token / base token price in human digestible form

Return type

decimal.Decimal

__init__(contract, token0, token1, reverse_token_order=None)
Parameters
Return type

None