Merge pull request locustio#12 from edx/jeskew/ci_robustness_fixes

Confidence interval robustness fixes.

locust/stats.py

@@ -550,19 +550,19 @@ def percentile(self, include_empty=True):
 
 
 class StatsError(object):
-    def __init__(self, method, name, error, occurences=0):
+    def __init__(self, method, name, error, occurrences=0):
         self.method = method
         self.name = name
         self.error = error
-        self.occurences = occurences
+        self.occurrences = occurrences
 
     @classmethod
     def create_key(cls, method, name, error):
         key = "%s.%s.%r" % (method, name, error)
         return hashlib.md5(key).hexdigest()
 
     def occured(self):
-        self.occurences += 1
+        self.occurrences += 1
 
     def to_name(self):
         return "%s %s: %r" % (self.method,
@@ -573,7 +573,7 @@ def to_dict(self):
             "method": self.method,
             "name": self.name,
             "error": repr(self.error),
-            "occurences": self.occurences
+            "occurrences": self.occurrences
         }
 
     @classmethod
@@ -582,7 +582,7 @@ def from_dict(cls, data):
             data["method"],
             data["name"],
             data["error"],
-            data["occurences"]
+            data["occurrences"]
         )
 
 
@@ -634,7 +634,7 @@ def on_slave_report(client_id, data, **kwargs):
         if error_key not in global_stats.errors:
             global_stats.errors[error_key] = StatsError.from_dict(error)
         else:
-            global_stats.errors[error_key].occurences += error["occurences"]
+            global_stats.errors[error_key].occurrences += error["occurrences"]
 
 events.request_success += on_request_success
 events.request_failure += on_request_failure
@@ -655,20 +655,24 @@ def print_percentile_stats(stats):
             new_col_name = "{0} (+/-)".format(
                 stats.percentile_column_name(percentile)
             )
-            data.append_col([
-                # We add 1e-9 to value, to prevent a division by zero error
-                "{0} (+{1:.2%}/-{2:.2%})".format(
-                    value,
-                    float('nan') if value == 0 else float(upper),
-                    float('nan') if value == 0 else float(lower),
-                )
-                for (value, upper, lower)
-                in zip(
-                    data[stats.percentile_column_name(percentile)],
-                    data[stats.confidence_interval_column_name(percentile)[1]],
-                    data[stats.confidence_interval_column_name(percentile)[0]],
-                )
-            ], header=new_col_name)
+            try:
+                data.append_col([
+                    # We add 1e-9 to value, to prevent a division by zero error
+                    "{0} (+{1:.2%}/-{2:.2%})".format(
+                        value,
+                        float('nan') if value == 0 or upper == 'N/A' else float(upper),
+                        float('nan') if value == 0 or lower == 'N/A' else float(lower),
+                    )
+                    for (value, upper, lower)
+                    in zip(
+                        data[stats.percentile_column_name(percentile)],
+                        data[stats.confidence_interval_column_name(percentile)[1]],
+                        data[stats.confidence_interval_column_name(percentile)[0]],
+                    )
+                ], header=new_col_name)
+            except IndexError:
+                # Attempted to insert an empty column.
+                continue
 
             del data[stats.percentile_column_name(percentile)]
             del data[stats.confidence_interval_column_name(percentile)[0]]
@@ -677,20 +681,22 @@ def print_percentile_stats(stats):
     # Move the 100% to the end
     values = data['100%']
     del data['100%']
-    data.append_col(values, header='100%')
+    if len(values):
+        data.append_col(values, header='100%')
 
-    console_logger.info("Percentage of the requests completed within given times")
-    console_logger.info(tabulate(data.dict, headers="keys"))
-    console_logger.info("")
+    if len(data.dict):
+        console_logger.info("Percentage of the requests completed within given times")
+        console_logger.info(tabulate(data.dict, headers="keys"))
+        console_logger.info("")
 
 def print_error_report():
     if not len(global_stats.errors):
         return
     console_logger.info("Error report")
-    console_logger.info(" %-18s %-100s" % ("# occurences", "Error"))
+    console_logger.info(" %-18s %-100s" % ("# occurrences", "Error"))
     console_logger.info("-" * (80 + STATS_NAME_WIDTH))
     for error in global_stats.errors.itervalues():
-        console_logger.info(" %-18i %-100s" % (error.occurences, error.to_name()))
+        console_logger.info(" %-18i %-100s" % (error.occurrences, error.to_name()))
     console_logger.info("-" * (80 + STATS_NAME_WIDTH))
     console_logger.info("")