how to write output of command "adb push file.txt /sdcard/" to text file?

how to write output of command "adb push file.txt /sdcard/" to text file?

Command :
adb push test.mp4 /sdcard/test.mp4
output of command :
2717 KB/s (17104177 bytes in 6.146s)
i want to write above output in one text file.
i tried following command :
adb push test.mp4 /sdcard/test.mp4 > Result.txt
but still Result.txt file is blank.
Please help, if you have any idea !!!
if solution is with using perl or python then also it is ok for me.