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A simple code complexity analyzer without caring about the C/C++ header files or Java imports. It can deal with Java/C/C++/JavaScript/Objective C code. It counts the cyclomatic complexity number etc.

Project description

Was hfcca, A Header Free Cyclomatic Complexity Analyzer.

Build Status

lizard is a simple code complexity analyzer without caring about the C/C++ header files or Java imports. It can deal with

  • C/C++
  • Java
  • JavaScript
  • Objective C.

It counts

  • the nloc (lines of code without comments),
  • CCN (cyclomatic complexity number),
  • token count of functions.
  • parameter count of functions.

You can set limitation for CCN (-C), the number of parameters (-a). Functions that exceed these limitations will generate warnings. The exit code of lizard will be none-Zero if there are warnings.

This tool actually calculates how complex the code ‘looks’ rather than how complex the code real ‘is’. People will need this tool because it’s often very hard to get all the included folders and files right when they are complicated. But we don’t really need that kind of accuracy for cyclomatic complexity.

It requires python2.7 or above (early versions are not verified).

Installation can be used as a stand alone Python script, most functionalities are there. You can always use it without any installation. To acquire all the functionalities of lizard, you will need a proper install.


If you want a proper install:

[sudo] pip install lizard

Or if you’ve got the source:

[sudo] python install


lizard [options] [PATH or FILE] [PATH] ...

Run for the code under current folder (recursively):


Exclude anything in the tests folder:

lizard mySource/ -x"./tests/*"


--version             show program's version number and exit
-h, --help            show this help message and exit
-v, --verbose         Output in verbose mode (long function name)
-C CCN, --CCN=CCN     Threshold for cyclomatic complexity number warning.
                      The default value is 15. Functions with CCN bigger
                      than this number will generate warning
                      Limit for number of parameters
-w, --warnings_only   Show warnings only, using clang/gcc's warning format
                      for printing warnings.
-i NUMBER, --ignore_warnings=NUMBER
                      If the number of warnings is equal or less than the
                      number, the tool will exit normally, otherwize it will
                      generate error. Useful in makefile when improving
                      legacy code.
-x EXCLUDE, --exclude=EXCLUDE
                      Exclude files that match this pattern. * matches
                      everything, ? matches any single characoter,
                      "./folder/*" exclude everything in the folder,
                      recursively. Multiple patterns can be specified. Don't
                      forget to add "" around the pattern.
-X, --xml             Generate XML in cppncss style instead of the normal
                      tabular output. Useful to generate report in Jenkins
-P, --no_preprocessor_count
                      By default, a #if will also increase the complexity.
                      Adding this option to ignore them
                      number of working threads. The default value is 1.
-d, --find_duplicates
                      Find and skip analysis for file duplicates.
-s, --sort
                      Sort the warning with field. The field can be nloc,
                      cyclomatic_complexity, token_count, parameter_count,
                      etc. Or an customized file.

Example use

Analyze a folder recursively: lizard mahjong_game/src

  NLOC    CCN  token  param    function@line@file
    10      2     29      2    start_new_player@26@./html_game.c
     6      1      3      0    set_shutdown_flag@449@./httpd.c
    24      3     61      1    server_main@454@./httpd.c
2 file analyzed.
LOC    Avg.NLOC AvgCCN Avg.ttoken  function_cnt    file
    191     15      3        51        12     ./html_game.c
    363     24      4        86        15     ./httpd.c

!!!! Warnings (CCN > 15) !!!!
    66     19    247      1    accept_request@64@./httpd.c
Total NLOC  Avg.NLOC  Avg CCN  Avg token  Fun Cnt  Warning cnt   Fun Rt   NLOC Rt
       554        20     4.07      71.15       27            1      0.04    0.12

Warnings only (in clang/gcc formation):lizard -w mahjong_game

./src/html_ui/httpd.c:64: warning: accept_request has 19 CCN and 1 params (66 NLOC, 247 tokens)
./src/mahjong_game/mj_table.c:109: warning: mj_table_update_state has 20 CCN and 1 params (72 NLOC, 255 tokens)

Using lizard as Python module

You can also use lizard as a Python module in your code:

>>> import lizard
>>> i = lizard.analyze_file("../cpputest/tests/AllTests.cpp")
>>> print i.__dict__
{'nloc': 9, 'function_list': [<lizard.FunctionInfo object at 0x10bf7af10>], 'filename': '../cpputest/tests/AllTests.cpp'}
>>> print i.function_list[0].__dict__
{'cyclomatic_complexity': 1, 'token_count': 22, 'name': 'main', 'parameter_count': 2, 'nloc': 3, 'long_name': 'main( int ac , const char ** av )', 'start_line': 30}

You can also use source code string instead of file. But you need to provide a file name (to identify the language).

>>> i = lizard.analyze_file.analyze_source_code("AllTests.cpp", "int foo(){}")


If for some reason you would like to ignore the warnings, you can use the whitelist. Add ‘whitelizard.txt’ to the current folder, then the functions defined in the file will be ignored. This is an example

#The file name can only be whitelizard.txt and put it in the current folder.
#You may have commented lines begin with #.
function_name1, function_name2 # list function names in mulitple lines or split with comma.
filename:function1, function2  # you can also specify the filename

Options in Comments

You can use options in the comments of the source code to change the behavior of lizard. By putting “#lizard forgives” inside a function or before a function it will suppress the warning for that function.

int foo() {
    // #lizard forgives the complexity

Wishlist (The features that will come in the near future)

Change Logs

  • 2014.03.31 Support JavaScript!
  • 2014.03.22 Change the -v (–verbose) option to -V. This is because -v will be used for –version.

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