chap3 - streaming write results in console

[maelfosso]

Hi,

I start learning Apache Spark by reading that book. I'm now at chapter 3 - Streaming part. For snippet code, I choose python3 My problem is that nothing is displayed in console, as said in the book, from that code

purchaseByCustomerPerHour.writeStream \
    .format("console") \
    .queryName("customer_purchases_3") \
    .outputMode("complete") \
    .start() \
    .show() 

I don't know if I'm doing something wrong but tell me how to display result in console at start and at every update too