Merge 319ba02 into e829532

docs/changes.rst

@@ -1,6 +1,15 @@
 Changes
 =======
 
+Version 1.7.15
+--------------
+
+* Add unit tests for randomtable, dummytable, and their supporting functions and classes
+  By :user:`bmos`, :issue:`657`.
+
+* Fix: DeprecationWarning: Seeding based on hashing is deprecated since Python 3.9 and will be removed in a subsequent version.
+  By :user:`bmos`, :issue:`657`.
+
 Version 1.7.14
 --------------
 

petl/test/util/test_random.py

@@ -0,0 +1,72 @@
+import random
+from functools import partial
+
+from petl.util.random import randomseed, randomtable, RandomTable, dummytable
+
+
+def test_randomseed():
+    s = randomseed()
+
+    assert isinstance(s, str)
+    assert s != ""
+
+
+def test_randomtable():
+    columns, rows = 3, 10
+    table = randomtable(columns, rows)
+
+    assert len(table[0]) == columns
+    assert len(table) == rows + 1
+
+
+def test_randomtable_class():
+    columns, rows = 4, 60
+    table = RandomTable(numflds=columns, numrows=rows)
+
+    assert len(table[0]) == columns
+    assert len(table) == rows + 1
+
+
+def test_dummytable_custom_fields():
+    columns = (
+        ('count', partial(random.randint, 0, 100)),
+        ('pet', partial(random.choice, ('dog', 'cat', 'cow'))),
+        ('color', partial(random.choice, ('yellow', 'orange', 'brown'))),
+        ('value', random.random)
+    )
+    rows = 35
+
+    table = dummytable(
+        numrows=rows,
+        fields=columns,
+    )
+    assert len(table[0]) == 4
+    assert len(table) == rows + 1
+
+
+def test_dummytable_no_seed():
+    rows = 35
+
+    table = dummytable(
+        numrows=rows,
+    )
+    assert len(table[0]) == 3
+    assert len(table) == rows + 1
+
+
+def test_dummytable_int_seed():
+    rows = 35
+
+    table = dummytable(
+        numrows=rows,
+        seed=42
+    )
+    assert len(table[0]) == 3
+    assert len(table) == rows + 1
+
+
+def test_dummytable_class():
+    rows = 70
+    table = dummytable(numrows=rows)
+
+    assert len(table) == rows + 1

petl/util/random.py

@@ -1,15 +1,24 @@
 from __future__ import absolute_import, print_function, division
 
-
-import datetime
+import hashlib
 import random
 import time
 from collections import OrderedDict
 from functools import partial
+
 from petl.compat import xrange, text_type
+from petl.util.base import Table
 
 
-from petl.util.base import Table
+def randomseed():
+    """
+    Obtain the hex digest of a sha256 hash of the
+    current epoch time in nanoseconds.
+    """
+
+    time_ns = str(time.time()).encode()
+    hash_time = hashlib.sha256(time_ns).hexdigest()
+    return hash_time
 
 
 def randomtable(numflds=5, numrows=100, wait=0, seed=None):
@@ -36,9 +45,11 @@ def randomtable(numflds=5, numrows=100, wait=0, seed=None):
         | 0.026535969683863625 |   0.1988376506866485 |  0.6498844377795232 |
         +----------------------+----------------------+---------------------+
         ...
+        <BLANKLINE>
 
     Note that the data are generated on the fly and are not stored in memory,
     so this function can be used to simulate very large tables.
+    The only supported seed types are: None, int, float, str, bytes, and bytearray.
 
     """
 
@@ -52,7 +63,7 @@ def __init__(self, numflds=5, numrows=100, wait=0, seed=None):
         self.numrows = numrows
         self.wait = wait
         if seed is None:
-            self.seed = datetime.datetime.now()
+            self.seed = randomseed()
         else:
             self.seed = seed
 
@@ -77,7 +88,7 @@ def __iter__(self):
             yield tuple(random.random() for n in range(nf))
 
     def reseed(self):
-        self.seed = datetime.datetime.now()
+        self.seed = randomseed()
 
 
 def dummytable(numrows=100,
@@ -108,6 +119,7 @@ def dummytable(numrows=100,
         |   4 | 'apples' |  0.09369523986159245 |
         +-----+----------+----------------------+
         ...
+        <BLANKLINE>
 
         >>> # customise fields
         ... import random
@@ -132,12 +144,19 @@ def dummytable(numrows=100,
         |  0.4219218196852704 |  15 | 'chocolate' |
         +---------------------+-----+-------------+
         ...
+        <BLANKLINE>
+
+        >>> table3_1 = etl.dummytable(50)
+        >>> table3_2 = etl.dummytable(100)
+        >>> table3_1[5] == table3_2[5]
+        False
 
     Data generation functions can be specified via the `fields` keyword
     argument.
 
     Note that the data are generated on the fly and are not stored in memory,
     so this function can be used to simulate very large tables.
+    The only supported seed types are: None, int, float, str, bytes, and bytearray.
 
     """
 
@@ -154,7 +173,7 @@ def __init__(self, numrows=100, fields=None, wait=0, seed=None):
         else:
             self.fields = OrderedDict(fields)
         if seed is None:
-            self.seed = datetime.datetime.now()
+            self.seed = randomseed()
         else:
             self.seed = seed
 
@@ -181,4 +200,4 @@ def __iter__(self):
             yield tuple(fields[f]() for f in fields)
 
     def reseed(self):
-        self.seed = datetime.datetime.now()
+        self.seed = randomseed()