By name: calculator description: "Math calculations, unit conversions, date/time arithmetic, and currency rates. Python-powered, no API needed for math." version: 1.0.0 metadata: echo: tags: [Math, Calculator, Units, Date, Currency, Utility]
Calculator
Math, units, dates, and currency conversion.
Math Expressions
Safe evaluation via Python:
import ast
result = eval(compile(ast.parse("2**10 + 3.14 * 2", mode='eval'), '', 'eval'))
Complex math:
import math
math.sqrt(144) # 12.0
math.log2(1024) # 10.0
math.factorial(10) # 3628800
math.pi # 3.14159...
Unit Conversions
| Category | Conversions |
|---|---|
| Temperature | C↔F: F = C*9/5+32 |
| Length | km↔mi (×0.621371), m↔ft (×3.28084), cm↔in (×0.393701) |
| Weight | kg↔lb (×2.20462), g↔oz (×0.035274) |
| Volume | L↔gal (×0.264172) |
| Data | KB↔MB↔GB↔TB (÷1024) |
Date Calculations
from datetime import datetime, timedelta
from zoneinfo import ZoneInfo
# Days between dates
(datetime(2026, 12, 31) - datetime.now()).days
# Add/subtract time
datetime.now() + timedelta(days=30, hours=2)
# Timezone conversion
dt = datetime.now(ZoneInfo("Asia/Shanghai"))
dt.astimezone(ZoneInfo("America/New_York"))
Currency Exchange
Free API (no key required):
curl -s "https://open.er-api.com/v6/latest/USD" | python3 -c "
import sys,json; d=json.load(sys.stdin)['rates']
print(f\"1 USD = {d['CNY']:.4f} CNY\")
print(f\"1 USD = {d['EUR']:.4f} EUR\")
print(f\"1 USD = {d['JPY']:.2f} JPY\")
"
Common Formulas
# BMI
bmi = weight_kg / (height_m ** 2)
# Compound interest
A = P * (1 + r/n) ** (n*t)
# Percentage change
change = (new - old) / old * 100
Script
python3 scripts/calc.py "2**32 - 1"
python3 scripts/calc.py convert 100 km mi
python3 scripts/calc.py date "2026-12-31" days-until
python3 scripts/calc.py currency 100 USD CNY