Stack Data Tool

Index of All Documentation » Wing Pro Reference Manual » Debugger » Viewing Debug Data »

The Stack Data tool can be used to view debug data for locals and globals. It contains a process, thread, and stack frame selection area, an expandable tree area for viewing data, and a details area for inspecting individual values as an array or in textual form.

Process, Thread, and Stack Frame Selector

The top part of the tool contains popup menus for selecting the current debug process, thread, and stack frame to focus on. The process selector is omitted in Wing 101 and Wing Personal, which do not support multi-process debugging. The thread selector is hidden unless there is more than one thread in the debug process.

This area also contains the Stack Data Options Menu.

Value Display

The value display area is shown below the stack selector area, and will contain the values for the currently selected process, thread, and stack frame. Each value or part of a value is shown as one line in the tree.

Simple values, such as strings and numbers, and values with a short string representation, are displayed in the Value column of the tree. Strings are always contained in "" (double quotes). Any value outside of quotes is the repr of an instance, a number, or a Python constant such as None or False. Integers can be displayed as decimal, hexadecimal, or octal, as controlled by the Debugger > Data Display > Integer Display Mode preference.

Complex values, such as instances, lists, and dictionaries, will be shown in a short form containing type and (optionally) the memory address, for example <dict 0x80ce388>. These can expanded by clicking on the expansion indicator in the Variable column. The memory address uniquely identifies the instance. If you see the same address in two places, you are looking at two object references to the same instance. Memory addresses may be hidden by toggling Show Memory Addresses in the tool's Options menu.

If a complex value is short enough to be displayed in its entirety, the <type address> form is replaced with its value, for example {'a': 'b'} for a small dictionary. These values can still be expanded from the Variable column. The size threshold used for this is set with the Debugger > Line Threshold preference. If you want all values to be shown uniformly, set this preference to 0.

Expanding Values

When a complex value is expanded, the position or name of each sub-value will be displayed in the Variable column, and the value of each sub-value (possibly also complex values) will be displayed in the Value column. Nested complex values can be expanded indefinitely, even if this results in the traversal of cycles of object references.

Once you expand a value, the debugger will continue to present that entry expanded, even after you step further or restart the debug session. Expansion state is saved and reused in later debug sessions, until you quit Wing.

Selected values can be viewed as an array or text by right-clicking on the item and choosing Show Value as Array or Show Value as Text. The content of the detail area is updated when other items in the Stack Data tool are selected. See Array and Textual Data Views for details.

Data Handling Errors

Wing may fail to show some data values because they are too large or can't be inspected safely. These are indicated in Stack Data in the following forms:

  • <huge sometype; len=10000> -- indicates a value of type sometype with given top-level length (if known) is too large to display because its overall size exceeds the Debugger > Data Display > Huge List Threshold or Huge String Threshold preferences. This may occur also for values with a small top-level size but which appear to generate a representation that large enough to hang up the debugger during data inspection.
  • <opaque sometype> -- indicates that a value of type sometype cannot be displayed because it is being filtered out by the Debugger > Data Filters > Do Not Expand preference or because settings described in Advanced Data Display prevent extraction of the value.
  • <verror sometype; code=xyz> -- indicates that a value of type sometype cannot be displayed because the debugger could not extract a displayable representation of the value. These value errors often indicate bugs in the code that implements the values Wing is trying to inspect. However, please report these errors using Submit Bug Report in Wing's Help menu or by sending email to Your report may enable us to improve Wing's data inspection facility to better handle the case you are seeing.

Some values that are too large for display in the Stack Data tool may still be viewed as arrays by right-clicking on the value and selecting Show Value as Array. Arrays are loaded incrementally according to what is visible on screen, and thus are less subject to size thresholds.

In Wing Pro you may also be able to use the Debug Console to access large or opaque values (for example try typing dir(varname)), or enter expressions into the Watch tool.

For details, see Problems Handling Values.

Section Contents