I found a better way. It is as described bellow. 

First create a module. I assume you know how to create a basic module. Then in vendor/module/view/frontend create requirejs-config.js with following code:



     var config = {
        "map": {
            "*": {
                
                "swiper": "Vendor_Module/js/swiper",
                "swiper_init": "Vendor_Module/js/swiper_init"
        
            
            }
        },
        "shim":{
           
            "Vendor_Module/js/swiper": ["jquery"]
        }
    };

Then place swiper.js and swiper_init.js in vendor/module/view/frontend/web/js

Swiper.js is the file you downloaded from Swiper repository and in swiper_init.js place following code:

    define([
        "jquery",
        "Vendor_Module/js/swiper"
       
    ], function($, Swiper){
         
         $.widget('vendor.module',{
         options: {
                
                
          },
        
         _create:function(config, element){
         //this.enableSwiper(false);
         
         var widget = this,
         options = this.getOptions(),
         swiper = new Swiper(this.element, options);
        
         
         swiper.init();
         
         },
       
        getOptions: function(){
            return this.options; 
         },
        
         });
        return $.vendor.module;
    });  

After that, add required classes to you phtml file

     <div class="swiper-container" data-mage-init='{"swiper_init":{
            	"direction": "horizontal",
                  "slidesPerView": 4, 
                  "spaceBetween": 40,
                  "centeredSlides": true,
                  "centeredSlidesBounds": true,
             	"breakpoints":{"375":{"slidesPerView":1},"768":{"slidesPerView":2},"1024":{"slidesPerView":1}}
                }
             }'
     <div class="product-items swiper-wrapper"> 
       <div class="product-item-info swiper-slide>
         .....your code to get products/images etc ......
       </div>
       </div>
    </div>

Save everything and setup:upgrade and all relevant Magento2 commands

You can also use it in any of your products widgets phtml files by declaring 

    <script type="text/x-magento-init">
    {
        "#swiper-container": {
            "swiper_init": :{
                	"direction": "horizontal",
                      "slidesPerView": 4, 
                      "spaceBetween": 40,
                      "centeredSlides": true,
                      "centeredSlidesBounds": true,
                 	"breakpoints":{"375":{"slidesPerView":1},"768":{"slidesPerView":2},"1024":{"slidesPerView":1}}
                    }
                 }
        }
       
    }
    </script>

 
Hope this help everyone. The best thing about this method is that it doens't use inline javascript.