What is the difference between the two built-in functions exec and eval in python3?

there are two built-in functions that have very similar functional descriptions: 

>>> help(exec)
Help on built-in function exec in module builtins:

exec(source, globals=None, locals=None, /)
    Execute the given source in the context of globals and locals.

    The source may be a string representing one or more Python statements
    or a code object as returned by compile().
    The globals must be a dictionary and locals can be any mapping,
    defaulting to the current globals and locals.
    If only globals is given, locals defaults to it.

I am so silly that I can"t tell the difference between a rookie and a rookie. I ask the big bird for advice on the difference between the two

Python python3.x
Mar.01,2021

eval returns the calculation result
exec only executes, but does not return the calculation result 

>>> a = eval('1+1')
>>> a
2
>>> exec('a=1+2')
>>> print a
3
>>> d = exec('1+4')
SyntaxError: invalid syntax
>>>

in addition to returning different results, eval only accepts a single expression, and exec can accept code blocks, loop control code blocks, exception code blocks, classes, and function definitions

.

Previous: Invalid weex1.2.9 settings entry file?

Next: The problem of low frame number of css3 Animation

css mysql arrays josn react html typescript webpack npm sass R objective-c .net sql-server jquery python-3.x angularjs django angular excel regex iphone ajax linux xml pandas vba spring database wordpress string wpf xcode windows bash postgresql oracle multithreading eclipse list firebase algorithm macos forms image scala visual-studio azure bootstrap spring-boot react-native python-2.7 docker performance function winforms matlab powershell apache dataframe api sqlite numpy rest shell selenium flutter dart maven loops qt swing android-studio csv express file class tensorflow sorting codeigniter perl
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b3084b-2bd26.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b3084b-2bd26.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?