ch07

2021-10-28 17:39:13 +05:30
parent b6eb3ef8a7
commit 32c12d89f4
11 changed files with 301 additions and 0 deletions
@@ -0,0 +1,46 @@
+# context/decimal.prec.py
+from decimal import Context, Decimal, getcontext, setcontext
+
+one = Decimal("1")
+three = Decimal("3")
+
+orig_ctx = getcontext()
+ctx = Context(prec=5)
+setcontext(ctx)
+print(ctx)
+print(one / three)
+setcontext(orig_ctx)
+print(one / three)
+
+
+"""
+$ python context/decimal.prec.py
+Context(prec=5, rounding=ROUND_HALF_EVEN, Emin=-999999,
+Emax=999999, capitals=1, clamp=0, flags=[],
+traps=[InvalidOperation, DivisionByZero, Overflow])
+0.33333
+0.3333333333333333333333333333
+"""
+
+
+orig_ctx = getcontext()
+ctx = Context(prec=5)
+setcontext(ctx)
+try:
+    print(ctx)
+    print(one / three)
+finally:
+    setcontext(orig_ctx)
+print(one / three)
+
+
+from decimal import localcontext
+
+with localcontext(Context(prec=5)) as ctx:
+    print(ctx)
+    print(one / three)
+print(one / three)
+
+
+with localcontext(Context(prec=5)), open("out.txt", "w") as out_f:
+    out_f.write(f"{one} / {three} = {one / three}\n")