When working with python a ImportError or ModuleNotFoundError: No module named 'xxx' may arise.
This error usually means that the script or python file you are running does not know about a module you are importing.
How can we get a list of modules that are accessible?
Using Sys Modules
This gets all package modules and sub modules:
import sys
modules = sys.modules
for key, value in modules.items():
print('module name', key)
print('module location', value)Get the module you are currently in:
print(self.__module__)Using Help
Set a breakpoint or print the below code in the code before the erroneous import
print(help('modules'))This displays all the modules available:
Please wait a moment while I gather a list of all available modules...
IPython ast importlib rst2xml
__future__ asynchat importlib_metadata rstpep2html
_abc asyncio iniconfig runpy
_ast asyncore inspect s3transfer
_asyncio atexit io sched
_bisect attr ipaddress secrets
_blake2 attrs ipdb select
_bootlocale audioop itertools selectors
_bz2 autoreload jedi setuptools
_codecs backcall jmespath shelve
_codecs_cn base64 jp shlex
_codecs_hk bdb json shutil
_codecs_iso2022 binascii keyword signal
_codecs_jp binhex lib2to3 site
_codecs_kr bisect linecache six
_codecs_tw boto3 locale smtpd
_collections botocore logging smtplib
_collections_abc builtins lzma sndhdr
_compat_pickle bz2 macpath sniffio
_compression cProfile mailbox socket
_contextvars calendar mailcap socketserver
_crypt certifi marshal sqlite3
_csv cgi math sre_compile
_ctypes cgitb matplotlib_inline sre_constants
_ctypes_test charset_normalizer mimetypes sre_parse
_curses chunk mmap ssl
_curses_panel cmath modulefinder stat
_datetime cmd multiprocessing statistics
_dbm code netrc storemagic
_decimal codecs nis string
_distutils_hack codeop nntplib stringprep
_dummy_thread collections ntpath struct
_elementtree colorama nturl2path subprocess
_functools colorsys numbers sunau
_hashlib compileall opcode symbol
_heapq concurrent operator sympyprinting
_imp configparser optparse symtable
_io contextlib os sys
_json contextvars packaging sysconfig
_locale copy parser syslog
_lsprof copyreg parso tabnanny
_lzma crypt pathlib tarfile
_markupbase csv pdb telnetlib
_md5 ctypes pexpect tempfile
_multibytecodec curses pickle termios
_multiprocessing cythonmagic pickleshare test
_opcode data pickletools test_parsing
_operator dataclasses pip tests
_osx_support datetime pipes textwrap
_pickle dateutil pkg_resources this
_posixsubprocess dbm pkgutil threading
_py_abc decimal platform time
_pydecimal decorator plistlib timeit
_pyio difflib pluggy tkinter
_pytest dis poplib token
_queue distutils posix tokenize
_random doctest posixpath toml
_scproxy docutils pprint tomli
_sha1 dummy_threading profile tornado
_sha256 elastic_transport prompt_toolkit trace
_sha3 elasticsearch pstats traceback
_sha512 elasticsearch5 pty tracemalloc
_signal email ptyprocess traitlets
_sitebuiltins encodings pwd tty
_socket ensurepip py turtle
_sqlite3 enum py_compile turtledemo
_sre errno pyasn1 types
_ssl faulthandler pyclbr typing
_stat fcntl pydoc typing_extensions
_string filecmp pydoc_data unicodedata
_strptime fileinput pyexpat unittest
_struct fnmatch pygments urllib
_symtable formatter pyparsing urllib3
_sysconfigdata_m_darwin_darwin fractions pytest uu
_testbuffer ftplib queue uuid
_testcapi functools quopri venv
_testimportmultiple gc random warnings
_testmultiphase genericpath re wave
_thread getopt readline wcwidth
_threading_local getpass reprlib weakref
_tkinter gettext requests webbrowser
_tracemalloc glob requests_aws4auth wheel
_uuid grp resource wsgiref
_virtualenv gzip rfc3986 xdrlib
_warnings h11 rlcompleter xml
_weakref hashlib rmagic xmlrpc
_weakrefset heapq rsa xxlimited
_xxtestfuzz hmac rst2html xxsubtype
_yaml html rst2html4 yaml
abc http rst2html5 zipapp
activate_this httpcore rst2latex zipfile
aifc httpx rst2man zipimport
antigravity idlelib rst2odt zipp
anyio idna rst2odt_prepstyles zlib
appnope imaplib rst2pseudoxml zmq
argparse imghdr rst2s5
array imp rst2xetex
Enter any module name to get more help. Or, type "modules spam" to search
for modules whose name or summary contain the string "spam".How can Python Find your Module?
If your module is not in the output above then python cannot find your module.
In that case you have 2 options:
- Explicitly add the path to your module/package
- Import your module relatively
First let us see all the current paths:
import sys
print(sys.path)If the path your module is in is not listed there you need to either add the path or structure your modules into a package.
To modify the path, use the PYTHONPATH environment variable. Example: PYTHONPATH=. pytest.
Multiple paths are separated with a
:on mac
Extra: List available Functions and Variable names
dir() returns the list of names in the current local scope
print(dir(__name__))output example:
['@py_builtins', '@pytest_ar', '__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__spec__']
['__add__', '__class__', '__contains__', '__delattr__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__getnewargs__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__iter__', '__le__', '__len__', '__lt__', '__mod__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__rmod__', '__rmul__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', 'capitalize', 'casefold', 'center', 'count', 'encode', 'endswith', 'expandtabs', 'find', 'format', 'format_map', 'index', 'isalnum', 'isalpha', 'isascii', 'isdecimal', 'isdigit', 'isidentifier', 'islower', 'isnumeric', 'isprintable', 'isspace', 'istitle', 'isupper', 'join', 'ljust', 'lower', 'lstrip', 'maketrans', 'partition', 'replace', 'rfind', 'rindex', 'rjust', 'rpartition', 'rsplit', 'rstrip', 'split', 'splitlines', 'startswith', 'strip', 'swapcase', 'title', 'translate', 'upper', 'zfill']Extra: Print the local symbol table:
Use locals()
print(locals())