why error in from gma.kin import cal_kin?

[xiahui625649]

`(base) xh@DESKTOP-O4AKJC8:/mnt/c/Users/XH/Desktop/gma-2019.4.20$ python
Python 2.7.16 |Anaconda, Inc.| (default, Mar 14 2019, 21:00:58)
[GCC 7.3.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.

import gma
from gma.kin import cal_kin
Traceback (most recent call last):
File "", line 1, in
File "gma/kin/init.py", line 1, in
from gma.kin.cal_kin import *
File "gma/kin/cal_kin.py", line 2, in
from pysnptools.snpreader import Bed
File "/home/xh/anaconda2/lib/python2.7/site-packages/pysnptools-0.5.3-py2.7.egg/pysnptools/snpreader/init.py", line 18, in
from pysnptools.snpreader.snpreader import SnpReader
File "/home/xh/anaconda2/lib/python2.7/site-packages/pysnptools-0.5.3-py2.7.egg/pysnptools/snpreader/snpreader.py", line 645
logging.info(f"reading {self.sid_count:,} SNPs in blocks of {block_size:,} and adding up kernels (for {self.iid_count:,} individuals) with {xp.name}.")
^
SyntaxError: invalid syntax
`