new tasks

Task/Determine_if_a_string_is_numeric/Python/determine_if_a_string_is_numeric-2.py

@@ -0,0 +1,3 @@
+s = '123'
+if s.isdigit():
+    # numeric

Task/Determine_if_a_string_is_numeric/Python/determine_if_a_string_is_numeric-3.py

@@ -0,0 +1,28 @@
+def is_numeric(lit):
+    'Return value of numeric literal string or ValueError exception'
+
+    # Handle '0'
+    if lit == '0': return 0
+    # Hex/Binary
+    litneg = lit[1:] if lit[0] == '-' else lit
+    if litneg[0] == '0':
+        if litneg[1] in 'xX':
+            return int(lit,16)
+        elif litneg[1] in 'bB':
+            return int(lit,2)
+        else:
+            try:
+                return int(lit,8)
+            except ValueError:
+                pass
+
+    # Int/Float/Complex
+    try:
+        return int(lit)
+    except ValueError:
+        pass
+    try:
+        return float(lit)
+    except ValueError:
+        pass
+    return complex(lit)

Task/Determine_if_a_string_is_numeric/Python/determine_if_a_string_is_numeric-4.py

@@ -0,0 +1,16 @@
+>>> for s in ['0', '00', '123', '-123.', '-123e-4', '0123', '0x1a1', '-123+4.5j', '0b0101', '0.123', '-0xabc', '-0b101']:
+    print "%14s -> %-14s %s" % ('"'+s+'"', is_numeric(s), type(is_numeric(s)))
+
+           "0" -> 0              <type 'int'>
+          "00" -> 0              <type 'int'>
+         "123" -> 123            <type 'int'>
+       "-123." -> -123.0         <type 'float'>
+     "-123e-4" -> -0.0123        <type 'float'>
+        "0123" -> 83             <type 'int'>
+       "0x1a1" -> 417            <type 'int'>
+   "-123+4.5j" -> (-123+4.5j)    <type 'complex'>
+      "0b0101" -> 5              <type 'int'>
+       "0.123" -> 0.123          <type 'float'>
+      "-0xabc" -> -2748          <type 'int'>
+      "-0b101" -> -5             <type 'int'>
+>>>

Task/Determine_if_a_string_is_numeric/Python/determine_if_a_string_is_numeric.py

@@ -0,0 +1,5 @@
+s = '123'
+try:
+    i = float(s)
+except ValueError, TypeError:
+    print 'not numeric'