Pycharm as a default git difftool and git mergetool on Windows. Add the following to ~/.gitconfig

.gitconfig

[diff]
    tool = pycharm
[difftool "pycharm"]
    cmd = "/c/Program\ Files/JetBrains/PyCharm 2019.1.1/bin/pycharm" diff "$LOCAL" "$REMOTE" && echo "Press enter to continue..." && read
[merge]
    tool = pycharm
    keepBackup = false
[mergetool "pycharm"]
    cmd = "/c/Program Files/JetBrains/PyCharm 2019.1.1/bin/pycharm" merge "$LOCAL" "$REMOTE" "$BASE" "$MERGED"