Mrthdrb

how i can override observer of other module(custom module)

to my another custom modules in magento 2

is it possible ???

Does anyone have an idea?

ex :

custom module 1:

the observer for catalog price change

custom module 2:

i want the price of changed by observer in custom module1.

Yes, you can using preference

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
 <preference for="Vendor1ModuelName1ObserverFileName1" type="Vendor2ModuelName2ObserverFileName2" />
</config>

Just copy the existing observer from FileName1.php to
FileName2.php and do alter the namespace and all. and I hope it works.

Despite executing first observer it will execute second observer.

Using Preference it's is possible

etc/di.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
 <preference for="Vendormodule1filelocation" type="Vendormodule2filelocation" /> 
</config>

To override an observer, I think better way is to use events.xml rather than using preference.

Suppose you have events.xml in ModuleA

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">
 <event name="some_event">
 <observer name="myObserverName" instance="MyCompanyModuleAObserverMyObserver" />
 </event>
</config>

Now if you want to override the observer MyCompanyModuleAObserverMyObserver, then create events.xml in your custom module as follows

<?xml version="1.0"?>
 <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">
 <event name="some_event">
 <observer name="myObserverName" instance="MyCompanyCustomModuleObserverMyObserver" />
 </event>
 </config>

And in your custom module's(MyCompany_CustomModule) module.xml add sequence of MyCompany_ModuleA

<?xml version="1.0" encoding="UTF-8" ?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
 <module name="MyCompany_CustomModule">
 <sequence>
 <module name="MyCompany_ModuleA" />
 </sequence>
 </module>
</config> 

Also, Magento recommends to use plugins for data modification. Observers should not be used for data modifications.