Introduce round_coin_value to simplify coin rounding

freqtrade/constants.py

@@ -45,6 +45,16 @@ USERPATH_NOTEBOOKS = 'notebooks'
 
 TELEGRAM_SETTING_OPTIONS = ['on', 'off', 'silent']
 
+
+# Define decimals per coin for outputs
+# Only used for outputs.
+DECIMAL_PER_COIN_FALLBACK = 3  # Should be low to avoid listing all possible FIAT's
+DECIMALS_PER_COIN = {
+    'BTC': 8,
+    'ETH': 5,
+}
+
+
 # Soure files with destination directories within user-directory
 USER_DATA_FILES = {
     'sample_strategy.py': USERPATH_STRATEGIES,

freqtrade/misc.py

@@ -11,10 +11,35 @@ from typing.io import IO
 
 import rapidjson
 
+from freqtrade.constants import DECIMAL_PER_COIN_FALLBACK, DECIMALS_PER_COIN
+
 
 logger = logging.getLogger(__name__)
 
 
+def decimals_per_coin(coin: str):
+    """
+    Helper method getting decimal amount for this coin
+    example usage: f".{decimals_per_coin('USD')}f"
+    :param coin: Which coin are we printing the price / value for
+    """
+    return DECIMALS_PER_COIN.get(coin, DECIMAL_PER_COIN_FALLBACK)
+
+
+def round_coin_value(value: float, coin: str, show_coin_name=True) -> str:
+    """
+    Get price value for this coin
+    :param value: Value to be printed
+    :param coin: Which coin are we printing the price / value for
+    :param show_coin_name: Return string in format: "222.22 USDT" or "222.22"
+    :return: Formatted / rounded value (with or without coin name)
+    """
+    if show_coin_name:
+        return f"{value:.{decimals_per_coin(coin)}f} {coin}"
+    else:
+        return f"{value:.{decimals_per_coin(coin)}f}"
+
+
 def shorten_date(_date: str) -> str:
     """
     Trim the date so it fits on small screens

freqtrade/optimize/optimize_reports.py

@@ -10,7 +10,7 @@ from tabulate import tabulate
 
 from freqtrade.constants import DATETIME_PRINT_FORMAT, LAST_BT_RESULT_FN
 from freqtrade.data.btanalysis import calculate_market_change, calculate_max_drawdown
-from freqtrade.misc import file_dump_json
+from freqtrade.misc import file_dump_json, round_coin_value, decimals_per_coin
 
 
 logger = logging.getLogger(__name__)
@@ -38,11 +38,12 @@ def store_backtest_stats(recordfilename: Path, stats: Dict[str, DataFrame]) -> N
     file_dump_json(latest_filename, {'latest_backtest': str(filename.name)})
 
 
-def _get_line_floatfmt() -> List[str]:
+def _get_line_floatfmt(stake_currency: str) -> List[str]:
     """
     Generate floatformat (goes in line with _generate_result_line())
     """
-    return ['s', 'd', '.2f', '.2f', '.8f', '.2f', 'd', 'd', 'd', 'd']
+    return ['s', 'd', '.2f', '.2f', f'.{decimals_per_coin(stake_currency)}f',
+            '.2f', 'd', 'd', 'd', 'd']
 
 
 def _get_line_header(first_column: str, stake_currency: str) -> List[str]:
@@ -352,7 +353,7 @@ def text_table_bt_results(pair_results: List[Dict[str, Any]], stake_currency: st
     """
 
     headers = _get_line_header('Pair', stake_currency)
-    floatfmt = _get_line_floatfmt()
+    floatfmt = _get_line_floatfmt(stake_currency)
     output = [[
         t['key'], t['trades'], t['profit_mean_pct'], t['profit_sum_pct'], t['profit_total_abs'],
         t['profit_total_pct'], t['duration_avg'], t['wins'], t['draws'], t['losses']
@@ -396,7 +397,7 @@ def text_table_strategy(strategy_results, stake_currency: str) -> str:
     :param all_results: Dict of <Strategyname: DataFrame> containing results for all strategies
     :return: pretty printed table with tabulate as string
     """
-    floatfmt = _get_line_floatfmt()
+    floatfmt = _get_line_floatfmt(stake_currency)
     headers = _get_line_header('Strategy', stake_currency)
 
     output = [[

tests/test_misc.py

@@ -6,9 +6,31 @@ from unittest.mock import MagicMock
 
 import pytest
 
-from freqtrade.misc import (file_dump_json, file_load_json, format_ms_time, pair_to_filename,
+from freqtrade.misc import (decimals_per_coin, file_dump_json, file_load_json, format_ms_time,
-                            plural, render_template, render_template_with_fallback,
+                            pair_to_filename, plural, render_template,
-                            safe_value_fallback, safe_value_fallback2, shorten_date)
+                            render_template_with_fallback, round_coin_value, safe_value_fallback,
+                            safe_value_fallback2, shorten_date)
+
+
+def test_decimals_per_coin():
+    assert decimals_per_coin('USDT') == 3
+    assert decimals_per_coin('EUR') == 3
+    assert decimals_per_coin('BTC') == 8
+    assert decimals_per_coin('ETH') == 5
+
+
+def test_round_coin_value():
+    assert round_coin_value(222.222222, 'USDT') == '222.222 USDT'
+    assert round_coin_value(222.2, 'USDT') == '222.200 USDT'
+    assert round_coin_value(222.12745, 'EUR') == '222.127 EUR'
+    assert round_coin_value(0.1274512123, 'BTC') == '0.12745121 BTC'
+    assert round_coin_value(0.1274512123, 'ETH') == '0.12745 ETH'
+
+    assert round_coin_value(222.222222, 'USDT', False) == '222.222'
+    assert round_coin_value(222.2, 'USDT', False) == '222.200'
+    assert round_coin_value(222.12745, 'EUR', False) == '222.127'
+    assert round_coin_value(0.1274512123, 'BTC', False) == '0.12745121'
+    assert round_coin_value(0.1274512123, 'ETH', False) == '0.12745'
 
 
 def test_shorten_date() -> None: