🐍 Python Errors

50 error notes

RuntimeError: An attempt has been made to start a new process before the current process has finished its bootstrapping phase

pythonmultiprocessingwindowsdebugging

pythonintermediate

Fixing SQLAlchemy PendingRollbackError: Stop the 'Poisoned Session' Cycle

sqlalchemy.exc.PendingRollbackError: Can't reconnect until invalid transaction is rolled back

pythonsqlalchemyfastapidatabase-errors

pythonintermediate

How to Fix NumPy's 'ValueError: operands could not be broadcast together'

ValueError: operands could not be broadcast together with shapes (3,) (4,)

pythonnumpybroadcastingdata-science

pythonbeginner

Fixing 'SyntaxError: f-string expression part cannot include a backslash' in Python

SyntaxError: f-string expression part cannot include a backslash

pythonf-stringsyntaxerrorcoding-tips

pythonbeginner

Fixing the 'Microsoft Visual C++ 14.0 or greater is required' Error on Windows

error: Microsoft Visual C++ 14.0 or greater is required. Get it with "Microsoft C++ Build Tools": https://visualstudio.microsoft.com/visual-cpp-build-tools/

pipwindowsvisual-c++python-errors

pythonbeginner

Handling ZeroDivisionError in Python: Practical Fixes and Prevention

ZeroDivisionError: division by zero

pythondebuggingpandasnumpy

pythonbeginner

Fix OSError: [Errno 98] Address already in use in Flask and FastAPI

OSError: [Errno 98] Address already in use

pythonflaskfastapisocket

pythonbeginner

Fix Python ValueError: could not convert string to float '1,234' — Locale Number Formats

ValueError: could not convert string to float: '1,234'

pythonfloatstringpandas

pythonintermediate

Fix 'RuntimeError: Working outside of application context' in Flask

RuntimeError: Working outside of application context. This typically means that you attempted to use functionality that needed to interface with the current application object in some way.

flaskpythonapp-contextruntimeerror

pythonbeginner

How to Fix 'TypeError: list indices must be integers or slices, not str' in Python

TypeError: list indices must be integers or slices, not str

pythondebuggingjsonbackend

pythonbeginner

Fixing Python's 'can't compare offset-naive and offset-aware datetimes' Error

TypeError: can't compare offset-naive and offset-aware datetimes

pythondatetimetimezonedjango

pythonbeginner

Fixing 'IndexError: list index out of range' in Python

IndexError: list index out of range

pythonlistindexerrordebugging

pythonintermediate

Fixing 'TypeError: cannot pickle' in Python Multiprocessing

TypeError: cannot pickle '<lambda>' object

pythonmultiprocessingpickleparallel

pythonbeginner

Fix 'TypeError: method() takes 1 positional argument but 2 were given' in Python

TypeError: my_method() takes 1 positional argument but 2 were given

pythonooptypeerrorclass

pythonbeginner

Fix 'error: externally-managed-environment' When Installing Python Packages with pip

error: externally-managed-environment

pythonpiplinuxvirtualenv

pythonbeginner

Fixing 'UnboundLocalError: local variable referenced before assignment' in Python

UnboundLocalError: local variable 'x' referenced before assignment

pythonvariable scopeunboundlocalerrorglobal

pythonbeginner

Solving Python's 'FileNotFoundError: [Errno 2]' Once and For All

FileNotFoundError: [Errno 2] No such file or directory: 'path/to/file.txt'

pythondebuggingpathlibfile-handling

pythonbeginner

Fixing the 'ParserError: Error tokenizing data' in Pandas

pandas.errors.ParserError: Error tokenizing data. C error: Expected 3 fields in line 12, saw 5

pythonpandascsvdata-science

pythonintermediate

Fix OSError: [Errno 24] Too many open files in Python

OSError: [Errno 24] Too many open files

pythonoserrorfile-descriptorresource-limit

pythonintermediate

Fix 'OverflowError: math range error' in Python with math.exp() and Large Numbers

OverflowError: math range error

pythonmathoverflowfloat

pythonintermediate

Fix 'JSONDecodeError: Expecting value: line 1 column 1 (char 0)' in Python

json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

pythonjsonjsondecodeerrorparsing

pythonbeginner

Fixing Python's PermissionError: [Errno 13] Permission Denied

PermissionError: [Errno 13] Permission denied: '/path/to/file'

pythonfile-handlingdevopstroubleshooting

pythonintermediate

Solving the Pandas SettingWithCopyWarning: Why Your DataFrame Updates Fail

SettingWithCopyWarning: A value is trying to be set on a copy of a slice from a DataFrame

pythonpandasdataframedata-science

pythonbeginner

Fix TypeError: 'NoneType' object is not iterable in Python

TypeError: 'NoneType' object is not iterable

pythontypeerrornoneiteration

pythonbeginner

Fixing Python’s 'ValueError: invalid literal for int() with base 10'

ValueError: invalid literal for int() with base 10: 'abc'

pythonvalueerrordata-cleaningbackend

pythonintermediate

Fixing the Python 'Max retries exceeded' ConnectionError

requests.exceptions.ConnectionError: HTTPSConnectionPool(host='...', port=443): Max retries exceeded with url

pythonrequestsapi-developmentnetworking

pythonintermediate

Stop the Crash: Fixing 'RuntimeError: generator raised StopIteration' in Python 3.7+

RuntimeError: generator raised StopIteration

pythongeneratorstopiterationpep479

pythonintermediate

Fixing 'UnicodeEncodeError: ascii codec can't encode character' in Python

UnicodeEncodeError: 'ascii' codec can't encode character '\u00e9' in position 1: ordinal not in range(128)

pythonunicodeencodingascii

pythonintermediate

Fix subprocess.CalledProcessError: Command Returned Non-Zero Exit Status in Python

subprocess.CalledProcessError: Command '['...']' returned non-zero exit status 1

pythonsubprocessshellprocess

pythonbeginner

Fix 'RuntimeWarning: coroutine was never awaited' in Python async/await

RuntimeWarning: coroutine 'xxx' was never awaited

pythonasynciocoroutineasync

pythonbeginner

Fix RuntimeError: dictionary changed size during iteration in Python

RuntimeError: dictionary changed size during iteration

pythonruntimeerrordictionaryiteration

pythonbeginner

Fix TypeError: unsupported operand type(s) for +: 'int' and 'str' in Python

TypeError: unsupported operand type(s) for +: 'int' and 'str'

pythontypeerrortype-conversiondebugging

pythonintermediate

Fix ImportError: cannot import name from partially initialized module (circular import) in Python

ImportError: cannot import name 'X' from partially initialized module 'Y' (most likely due to a circular import)

pythonimportcircular-importmodule

pythonbeginner

Fix Python UnicodeDecodeError: 'utf-8' codec can't decode byte

UnicodeDecodeError: 'utf-8' codec can't decode byte

pythonunicodeencoding

pythonintermediate

Fix Python MemoryError When Processing Large Data

MemoryError

pythonmemoryperformancelarge-data

pythonbeginner

Fix ssl.SSLCertVerificationError: certificate verify failed in Python HTTPS Requests

ssl.SSLCertVerificationError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1129)

pythonsslrequestshttps

pythonbeginner

Fix Python KeyError: 'key_name' When Accessing a Dictionary

KeyError: 'key_name'

pythonkeyerrordictionary

pythonintermediate

Fix Python RecursionError: maximum recursion depth exceeded

RecursionError: maximum recursion depth exceeded

pythonrecursionsys

pythonbeginner

Fix Python TypeError: 'str' object is not callable

TypeError: 'str' object is not callable

pythontypeerrorfunctionvariable

pythonbeginner

Fix Python ValueError: too many values to unpack (expected 2)

ValueError: too many values to unpack (expected 2)

pythontupleunpackinglist

pythonbeginner

Fix AttributeError: 'NoneType' object has no attribute in Python

AttributeError: 'NoneType' object has no attribute 'split'

pythonattributeerrornonetypedebugging

pythonbeginner

Fix 'IndentationError: expected an indented block' in Python

IndentationError: expected an indented block

pythonindentationsyntax

pythonbeginner

Fix ModuleNotFoundError: No module named 'xxx' in Python

ModuleNotFoundError: No module named 'xxx'

pythonpipimportvirtualenv

🐍 Python Errors

How to Fix 'sqlite3.OperationalError: database is locked' in Python

Fixing 'AttributeError: module collections has no attribute Callable' in Python 3.10+

How to Fix 'TypeError: 'dict_keys' object is not subscriptable' in Python

Fixing 'RuntimeError: no running event loop' in Python 3.10, 3.11, and 3.12

Fixing the Python Multiprocessing 'RuntimeError' on Windows

Fixing SQLAlchemy PendingRollbackError: Stop the 'Poisoned Session' Cycle

How to Fix NumPy's 'ValueError: operands could not be broadcast together'

Fixing 'SyntaxError: f-string expression part cannot include a backslash' in Python

Fixing the 'Microsoft Visual C++ 14.0 or greater is required' Error on Windows

Handling ZeroDivisionError in Python: Practical Fixes and Prevention

Fix OSError: [Errno 98] Address already in use in Flask and FastAPI

Fix Python ValueError: could not convert string to float '1,234' — Locale Number Formats

Fix 'RuntimeError: Working outside of application context' in Flask

Fix TypeError: 'type' object is not subscriptable in Python Type Hints

Fixing 'TypeError: Object of type datetime is not JSON serializable' in Python

Fixing 'ConnectionRefusedError: [Errno 111] Connection refused' in Python

How to Fix 'TypeError: list indices must be integers or slices, not str' in Python

Fixing Python's 'can't compare offset-naive and offset-aware datetimes' Error

Fixing 'IndexError: list index out of range' in Python

Fixing 'TypeError: cannot pickle' in Python Multiprocessing

Fix 'TypeError: method() takes 1 positional argument but 2 were given' in Python

Fix 'error: externally-managed-environment' When Installing Python Packages with pip

Fixing 'UnboundLocalError: local variable referenced before assignment' in Python

Solving Python's 'FileNotFoundError: [Errno 2]' Once and For All

Fixing the 'ParserError: Error tokenizing data' in Pandas

Fix OSError: [Errno 24] Too many open files in Python

Fix 'OverflowError: math range error' in Python with math.exp() and Large Numbers

Fix 'JSONDecodeError: Expecting value: line 1 column 1 (char 0)' in Python

Fixing Python's PermissionError: [Errno 13] Permission Denied

Solving the Pandas SettingWithCopyWarning: Why Your DataFrame Updates Fail

Fix TypeError: 'NoneType' object is not iterable in Python

Fixing Python’s 'ValueError: invalid literal for int() with base 10'

Fixing the Python 'Max retries exceeded' ConnectionError

Stop the Crash: Fixing 'RuntimeError: generator raised StopIteration' in Python 3.7+

Fixing 'UnicodeEncodeError: ascii codec can't encode character' in Python

Fix subprocess.CalledProcessError: Command Returned Non-Zero Exit Status in Python

Fix 'RuntimeWarning: coroutine was never awaited' in Python async/await

Fix RuntimeError: dictionary changed size during iteration in Python

Fix TypeError: unsupported operand type(s) for +: 'int' and 'str' in Python

Fix ImportError: cannot import name from partially initialized module (circular import) in Python

Fix Python UnicodeDecodeError: 'utf-8' codec can't decode byte

Fix Python MemoryError When Processing Large Data

Fix ssl.SSLCertVerificationError: certificate verify failed in Python HTTPS Requests

Fix Python KeyError: 'key_name' When Accessing a Dictionary

Fix Python RecursionError: maximum recursion depth exceeded

Fix Python TypeError: 'str' object is not callable

Fix Python ValueError: too many values to unpack (expected 2)

Fix AttributeError: 'NoneType' object has no attribute in Python

Fix 'IndentationError: expected an indented block' in Python

Fix ModuleNotFoundError: No module named 'xxx' in Python