There were several different spellings of MicroPython present in comments, when there should be only one.
Without this, spi.read(1, 0xff) would use 16 clock cycles, first to send 0xff and then to receive one byte, as visible with a logic analyzer.
This module uses ESP8266's SPI hardware, which allows much higher speeds. It uses a library from https://github.com/MetalPhreak/ESP8266_SPI_Driver