Specifying source files¶
When coverage.py is running your program and measuring its execution, it needs to know what code to measure and what code not to. Measurement imposes a speed penalty, and the collected data must be stored in memory and then on disk. More importantly, when reviewing your coverage reports, you don’t want to be distracted with modules that aren’t your concern.
Coverage.py has a number of ways you can focus it in on the code you care about.
When running your code, the
coverage run command will by default measure
all code, unless it is part of the Python standard library.
You can specify source to measure with the
--source command-line switch, or
[run] source configuration value. The value is a comma- or
newline-separated list of directories or importable names (packages or
If the source option is specified,
only code in those locations will be measured.
Specifying the source option also enables coverage.py to report on unexecuted
files, since it can search the source tree for files that haven’t been measured
at all. Only importable files (ones at the root of the tree, or in directories
__init__.py file) will be considered. Files with unusual punctuation
in their names will be skipped (they are assumed to be scratch files written by
text editors). Files that do not end with
.pyc will also be skipped.
Modules named as sources may be imported twice, once by coverage.py to find their location, then again by your own code or test suite. Usually this isn’t a problem, but could cause trouble if a module has side-effects at import time.
You can further fine-tune coverage.py’s attention with the
--omit switches (or
[run] include and
[run] omit configuration
--include is a list of file name patterns. If specified, only
files matching those patterns will be measured.
--omit is also a list of
file name patterns, specifying files not to measure. If both
omit are specified, first the set of files is reduced to only those that
match the include patterns, then any files that match the omit pattern are
removed from the set.
omit file name patterns follow typical shell syntax:
* matches any number of characters and
? matches a single character.
Patterns that start with a wildcard character are used as-is, other patterns
are interpreted relative to the current directory:
[run] omit = # omit anything in a .local directory anywhere */.local/* # omit everything in /usr /usr/* # omit this single file utils/tirefire.py
omit values all work together to determine
the source that will be measured.
include are set, the
include value is ignored
and a warning is printed on the standard output.
Once your program is measured, you can specify the source files you want reported. Usually you want to see all the code that was measured, but if you are measuring a large project, you may want to get reports for just certain parts.
The report commands (
all take optional
modules arguments, and
modules arguments specify particular modules to report on.
omit values are lists of file name patterns, just as
Remember that the reporting commands can only report on the data that has been collected, so the data you’re looking for may not be in the data available for reporting.
Note that these are ways of specifying files to measure. You can also exclude individual source lines. See Excluding code from coverage.py for details.