I created an app on the DigitalOcean App Platform with a requirements.txt and a Procfile - causing it to detect a Python application and build the app with their Python buildpack.
Here are some details of the resulting environment, from running commands using the DigitalOcean web terminal.
$ uname -a
Linux digital-ocean-app-9c6bd5794-kt9h8 4.4.0 #1 SMP Sun Jan 10 15:06:54 PST 2016 x86_64 x86_64 x86_64 GNU/Linux
$ cat /etc/issue
Ubuntu 18.04.5 LTS \n \l
$ apt list --installed
adduser/now 3.116ubuntu1 all [installed,local]
apt/now 1.6.12ubuntu0.1 amd64 [installed,local]
apt-transport-https/now 1.6.12ubuntu0.1 all [installed,local]
apt-utils/now 1.6.12ubuntu0.1 amd64 [installed,local]
base-files/now 10.1ubuntu2.10 amd64 [installed,local]
base-passwd/now 3.5.44 amd64 [installed,local]
bash/now 4.4.18-2ubuntu1.2 amd64 [installed,local]
bind9-host/now 1:9.11.3+dfsg-1ubuntu1.13 amd64 [installed,local]
binutils/now 2.30-21ubuntu1~18.04.4 amd64 [installed,local]
binutils-common/now 2.30-21ubuntu1~18.04.4 amd64 [installed,local]
binutils-x86-64-linux-gnu/now 2.30-21ubuntu1~18.04.4 amd64 [installed,local]
bsdutils/now 1:2.31.1-0.4ubuntu3.7 amd64 [installed,local]
bzip2/now 1.0.6-8.1ubuntu0.2 amd64 [installed,local]
ca-certificates/now 20190110~18.04.1 all [installed,local]
coreutils/now 8.28-1ubuntu1 amd64 [installed,local]
cpp/now 4:7.4.0-1ubuntu2.3 amd64 [installed,local]
cpp-7/now 7.5.0-3ubuntu1~18.04 amd64 [installed,local]
curl/now 7.58.0-2ubuntu3.10 amd64 [installed,local]
dash/now 0.5.8-2.10 amd64 [installed,local]
debconf/now 1.5.66ubuntu1 all [installed,local]
debianutils/now 4.8.4 amd64 [installed,local]
diffutils/now 1:3.6-1 amd64 [installed,local]
dirmngr/now 2.2.4-1ubuntu1.3 amd64 [installed,local]
distro-info-data/now 0.37ubuntu0.7 all [installed,local]
dnsutils/now 1:9.11.3+dfsg-1ubuntu1.13 amd64 [installed,local]
dpkg/now 1.19.0.5ubuntu2.3 amd64 [installed,local]
e2fsprogs/now 1.44.1-1ubuntu1.3 amd64 [installed,local]
ed/now 1.10-2.1 amd64 [installed,local]
fdisk/now 2.31.1-0.4ubuntu3.7 amd64 [installed,local]
file/now 1:5.32-2ubuntu0.4 amd64 [installed,local]
findutils/now 4.6.0+git+20170828-2 amd64 [installed,local]
fontconfig/now 2.12.6-0ubuntu2 amd64 [installed,local]
fontconfig-config/now 2.12.6-0ubuntu2 all [installed,local]
fonts-dejavu-core/now 2.37-1 all [installed,local]
gcc/now 4:7.4.0-1ubuntu2.3 amd64 [installed,local]
gcc-7/now 7.5.0-3ubuntu1~18.04 amd64 [installed,local]
gcc-7-base/now 7.5.0-3ubuntu1~18.04 amd64 [installed,local]
gcc-8-base/now 8.4.0-1ubuntu1~18.04 amd64 [installed,local]
geoip-database/now 20180315-1 all [installed,local]
ghostscript/now 9.26~dfsg+0-0ubuntu0.18.04.13 amd64 [installed,local]
git/now 1:2.17.1-1ubuntu0.7 amd64 [installed,local]
git-man/now 1:2.17.1-1ubuntu0.7 all [installed,local]
gnupg/now 2.2.4-1ubuntu1.3 amd64 [installed,local]
gnupg-l10n/now 2.2.4-1ubuntu1.3 all [installed,local]
gnupg-utils/now 2.2.4-1ubuntu1.3 amd64 [installed,local]
gpg/now 2.2.4-1ubuntu1.3 amd64 [installed,local]
gpg-agent/now 2.2.4-1ubuntu1.3 amd64 [installed,local]
gpg-wks-client/now 2.2.4-1ubuntu1.3 amd64 [installed,local]
gpg-wks-server/now 2.2.4-1ubuntu1.3 amd64 [installed,local]
gpgconf/now 2.2.4-1ubuntu1.3 amd64 [installed,local]
gpgsm/now 2.2.4-1ubuntu1.3 amd64 [installed,local]
gpgv/now 2.2.4-1ubuntu1.3 amd64 [installed,local]
grep/now 3.1-2build1 amd64 [installed,local]
gsfonts/now 1:8.11+urwcyr1.0.7~pre44-4.4 all [installed,local]
gzip/now 1.6-5ubuntu1 amd64 [installed,local]
hicolor-icon-theme/now 0.17-2 all [installed,local]
hostname/now 3.20 amd64 [installed,local]
imagemagick/now 8:6.9.7.4+dfsg-16ubuntu6.8 amd64 [installed,local]
imagemagick-6-common/now 8:6.9.7.4+dfsg-16ubuntu6.8 all [installed,local]
imagemagick-6.q16/now 8:6.9.7.4+dfsg-16ubuntu6.8 amd64 [installed,local]
init-system-helpers/now 1.51 all [installed,local]
iproute2/now 4.15.0-2ubuntu1.2 amd64 [installed,local]
iputils-tracepath/now 3:20161105-1ubuntu3 amd64 [installed,local]
language-pack-en/now 1:18.04+20190718 all [installed,local]
language-pack-en-base/now 1:18.04+20180712 all [installed,local]
less/now 487-0.1 amd64 [installed,local]
libacl1/now 2.2.52-3build1 amd64 [installed,local]
libapt-inst2.0/now 1.6.12ubuntu0.1 amd64 [installed,local]
libapt-pkg5.0/now 1.6.12ubuntu0.1 amd64 [installed,local]
libargon2-0/now 0~20161029-1.1 amd64 [installed,local]
libasan4/now 7.5.0-3ubuntu1~18.04 amd64 [installed,local]
libasn1-8-heimdal/now 7.5.0+dfsg-1 amd64 [installed,local]
libassuan0/now 2.5.1-2 amd64 [installed,local]
libatomic1/now 8.4.0-1ubuntu1~18.04 amd64 [installed,local]
libattr1/now 1:2.4.47-2build1 amd64 [installed,local]
libaudit-common/now 1:2.8.2-1ubuntu1 all [installed,local]
libaudit1/now 1:2.8.2-1ubuntu1 amd64 [installed,local]
libavahi-client3/now 0.7-3.1ubuntu1.2 amd64 [installed,local]
libavahi-common-data/now 0.7-3.1ubuntu1.2 amd64 [installed,local]
libavahi-common3/now 0.7-3.1ubuntu1.2 amd64 [installed,local]
libbind9-160/now 1:9.11.3+dfsg-1ubuntu1.13 amd64 [installed,local]
libbinutils/now 2.30-21ubuntu1~18.04.4 amd64 [installed,local]
libblkid1/now 2.31.1-0.4ubuntu3.7 amd64 [installed,local]
libbsd0/now 0.8.7-1ubuntu0.1 amd64 [installed,local]
libbz2-1.0/now 1.0.6-8.1ubuntu0.2 amd64 [installed,local]
libc-bin/now 2.27-3ubuntu1.2 amd64 [installed,local]
libc-client2007e/now 8:2007f~dfsg-5ubuntu0.18.04.2 amd64 [installed,local]
libc-dev-bin/now 2.27-3ubuntu1.2 amd64 [installed,local]
libc6/now 2.27-3ubuntu1.2 amd64 [installed,local]
libc6-dev/now 2.27-3ubuntu1.2 amd64 [installed,local]
libcairo2/now 1.15.10-2ubuntu0.1 amd64 [installed,local]
libcap-ng0/now 0.7.7-3.1 amd64 [installed,local]
libcap2/now 1:2.25-1.2 amd64 [installed,local]
libcc1-0/now 8.4.0-1ubuntu1~18.04 amd64 [installed,local]
libcilkrts5/now 7.5.0-3ubuntu1~18.04 amd64 [installed,local]
libcom-err2/now 1.44.1-1ubuntu1.3 amd64 [installed,local]
libcroco3/now 0.6.12-2 amd64 [installed,local]
libcups2/now 2.2.7-1ubuntu2.8 amd64 [installed,local]
libcupsimage2/now 2.2.7-1ubuntu2.8 amd64 [installed,local]
libcurl3-gnutls/now 7.58.0-2ubuntu3.10 amd64 [installed,local]
libcurl4/now 7.58.0-2ubuntu3.10 amd64 [installed,local]
libdatrie1/now 0.2.10-7 amd64 [installed,local]
libdb5.3/now 5.3.28-13.1ubuntu1.1 amd64 [installed,local]
libdbus-1-3/now 1.12.2-1ubuntu1.2 amd64 [installed,local]
libdebconfclient0/now 0.213ubuntu1 amd64 [installed,local]
libdjvulibre-text/now 3.5.27.1-8ubuntu0.2 all [installed,local]
libdjvulibre21/now 3.5.27.1-8ubuntu0.2 amd64 [installed,local]
libdns1100/now 1:9.11.3+dfsg-1ubuntu1.13 amd64 [installed,local]
libedit2/now 3.1-20170329-1 amd64 [installed,local]
libelf1/now 0.170-0.4ubuntu0.1 amd64 [installed,local]
liberror-perl/now 0.17025-1 all [installed,local]
libev4/now 1:4.22-1 amd64 [installed,local]
libevent-2.1-6/now 2.1.8-stable-4build1 amd64 [installed,local]
libevent-core-2.1-6/now 2.1.8-stable-4build1 amd64 [installed,local]
libevent-extra-2.1-6/now 2.1.8-stable-4build1 amd64 [installed,local]
libevent-openssl-2.1-6/now 2.1.8-stable-4build1 amd64 [installed,local]
libevent-pthreads-2.1-6/now 2.1.8-stable-4build1 amd64 [installed,local]
libexif12/now 0.6.21-4ubuntu0.5 amd64 [installed,local]
libexpat1/now 2.2.5-3ubuntu0.2 amd64 [installed,local]
libext2fs2/now 1.44.1-1ubuntu1.3 amd64 [installed,local]
libfdisk1/now 2.31.1-0.4ubuntu3.7 amd64 [installed,local]
libffi6/now 3.2.1-8 amd64 [installed,local]
libfftw3-double3/now 3.3.7-1 amd64 [installed,local]
libfontconfig1/now 2.12.6-0ubuntu2 amd64 [installed,local]
libfreetype6/now 2.8.1-2ubuntu2 amd64 [installed,local]
libgcc-7-dev/now 7.5.0-3ubuntu1~18.04 amd64 [installed,local]
libgcc1/now 1:8.4.0-1ubuntu1~18.04 amd64 [installed,local]
libgcrypt20/now 1.8.1-4ubuntu1.2 amd64 [installed,local]
libgd3/now 2.2.5-4ubuntu0.4 amd64 [installed,local]
libgdbm-compat4/now 1.14.1-6 amd64 [installed,local]
libgdbm5/now 1.14.1-6 amd64 [installed,local]
libgdk-pixbuf2.0-0/now 2.36.11-2 amd64 [installed,local]
libgdk-pixbuf2.0-common/now 2.36.11-2 all [installed,local]
libgeoip1/now 1.6.12-1 amd64 [installed,local]
libglib2.0-0/now 2.56.4-0ubuntu0.18.04.6 amd64 [installed,local]
libgmp10/now 2:6.1.2+dfsg-2 amd64 [installed,local]
libgnutls-openssl27/now 3.5.18-1ubuntu1.4 amd64 [installed,local]
libgnutls30/now 3.5.18-1ubuntu1.4 amd64 [installed,local]
libgnutlsxx28/now 3.5.18-1ubuntu1.4 amd64 [installed,local]
libgomp1/now 8.4.0-1ubuntu1~18.04 amd64 [installed,local]
libgpg-error0/now 1.27-6 amd64 [installed,local]
libgraphite2-3/now 1.3.11-2 amd64 [installed,local]
libgs9/now 9.26~dfsg+0-0ubuntu0.18.04.13 amd64 [installed,local]
libgs9-common/now 9.26~dfsg+0-0ubuntu0.18.04.13 all [installed,local]
libgssapi-krb5-2/now 1.16-2ubuntu0.1 amd64 [installed,local]
libgssapi3-heimdal/now 7.5.0+dfsg-1 amd64 [installed,local]
libharfbuzz0b/now 1.7.2-1ubuntu1 amd64 [installed,local]
libhcrypto4-heimdal/now 7.5.0+dfsg-1 amd64 [installed,local]
libheimbase1-heimdal/now 7.5.0+dfsg-1 amd64 [installed,local]
libheimntlm0-heimdal/now 7.5.0+dfsg-1 amd64 [installed,local]
libhogweed4/now 3.4-1 amd64 [installed,local]
libhx509-5-heimdal/now 7.5.0+dfsg-1 amd64 [installed,local]
libicu60/now 60.2-3ubuntu3.1 amd64 [installed,local]
libidn11/now 1.33-2.1ubuntu1.2 amd64 [installed,local]
libidn2-0/now 2.0.4-1.1ubuntu0.2 amd64 [installed,local]
libijs-0.35/now 0.35-13 amd64 [installed,local]
libilmbase12/now 2.2.0-11ubuntu2 amd64 [installed,local]
libirs160/now 1:9.11.3+dfsg-1ubuntu1.13 amd64 [installed,local]
libisc169/now 1:9.11.3+dfsg-1ubuntu1.13 amd64 [installed,local]
libisccc160/now 1:9.11.3+dfsg-1ubuntu1.13 amd64 [installed,local]
libisccfg160/now 1:9.11.3+dfsg-1ubuntu1.13 amd64 [installed,local]
libisl19/now 0.19-1 amd64 [installed,local]
libitm1/now 8.4.0-1ubuntu1~18.04 amd64 [installed,local]
libjbig0/now 2.1-3.1build1 amd64 [installed,local]
libjbig2dec0/now 0.13-6 amd64 [installed,local]
libjpeg-turbo8/now 1.5.2-0ubuntu5.18.04.4 amd64 [installed,local]
libjpeg8/now 8c-2ubuntu8 amd64 [installed,local]
libjson-c3/now 0.12.1-1.3ubuntu0.3 amd64 [installed,local]
libk5crypto3/now 1.16-2ubuntu0.1 amd64 [installed,local]
libkeyutils1/now 1.5.9-9.2ubuntu2 amd64 [installed,local]
libkrb5-26-heimdal/now 7.5.0+dfsg-1 amd64 [installed,local]
libkrb5-3/now 1.16-2ubuntu0.1 amd64 [installed,local]
libkrb5support0/now 1.16-2ubuntu0.1 amd64 [installed,local]
libksba8/now 1.3.5-2 amd64 [installed,local]
liblcms2-2/now 2.9-1ubuntu0.1 amd64 [installed,local]
libldap-2.4-2/now 2.4.45+dfsg-1ubuntu1.6 amd64 [installed,local]
libldap-common/now 2.4.45+dfsg-1ubuntu1.6 all [installed,local]
liblqr-1-0/now 0.4.2-2.1 amd64 [installed,local]
liblsan0/now 8.4.0-1ubuntu1~18.04 amd64 [installed,local]
libltdl7/now 2.4.6-2 amd64 [installed,local]
liblwres160/now 1:9.11.3+dfsg-1ubuntu1.13 amd64 [installed,local]
liblz4-1/now 0.0~r131-2ubuntu3 amd64 [installed,local]
liblzma5/now 5.2.2-1.3 amd64 [installed,local]
libmagic-mgc/now 1:5.32-2ubuntu0.4 amd64 [installed,local]
libmagic1/now 1:5.32-2ubuntu0.4 amd64 [installed,local]
libmagickcore-6.q16-3/now 8:6.9.7.4+dfsg-16ubuntu6.8 amd64 [installed,local]
libmagickcore-6.q16-3-extra/now 8:6.9.7.4+dfsg-16ubuntu6.8 amd64 [installed,local]
libmagickwand-6.q16-3/now 8:6.9.7.4+dfsg-16ubuntu6.8 amd64 [installed,local]
libmcrypt4/now 2.5.8-3.3 amd64 [installed,local]
libmemcached11/now 1.0.18-4.2ubuntu0.18.04.1 amd64 [installed,local]
libmnl0/now 1.0.4-2 amd64 [installed,local]
libmount1/now 2.31.1-0.4ubuntu3.7 amd64 [installed,local]
libmpc3/now 1.1.0-1 amd64 [installed,local]
libmpdec2/now 2.4.2-1ubuntu1 amd64 [installed,local]
libmpfr6/now 4.0.1-1 amd64 [installed,local]
libmpx2/now 8.4.0-1ubuntu1~18.04 amd64 [installed,local]
libmysqlclient20/now 5.7.31-0ubuntu0.18.04.1 amd64 [installed,local]
libncurses5/now 6.1-1ubuntu1.18.04 amd64 [installed,local]
libncursesw5/now 6.1-1ubuntu1.18.04 amd64 [installed,local]
libnettle6/now 3.4-1 amd64 [installed,local]
libnghttp2-14/now 1.30.0-1ubuntu1 amd64 [installed,local]
libnpth0/now 1.5-3 amd64 [installed,local]
libonig4/now 6.7.0-1 amd64 [installed,local]
libopenexr22/now 2.2.0-11.1ubuntu1.3 amd64 [installed,local]
libp11-kit0/now 0.23.9-2 amd64 [installed,local]
libpam-modules/now 1.1.8-3.6ubuntu2.18.04.2 amd64 [installed,local]
libpam-modules-bin/now 1.1.8-3.6ubuntu2.18.04.2 amd64 [installed,local]
libpam-runtime/now 1.1.8-3.6ubuntu2.18.04.2 all [installed,local]
libpam0g/now 1.1.8-3.6ubuntu2.18.04.2 amd64 [installed,local]
libpango-1.0-0/now 1.40.14-1ubuntu0.1 amd64 [installed,local]
libpangocairo-1.0-0/now 1.40.14-1ubuntu0.1 amd64 [installed,local]
libpangoft2-1.0-0/now 1.40.14-1ubuntu0.1 amd64 [installed,local]
libpaper1/now 1.1.24+nmu5ubuntu1 amd64 [installed,local]
libpcre3/now 2:8.39-9 amd64 [installed,local]
libperl5.26/now 5.26.1-6ubuntu0.3 amd64 [installed,local]
libpixman-1-0/now 0.34.0-2 amd64 [installed,local]
libpng16-16/now 1.6.34-1ubuntu0.18.04.2 amd64 [installed,local]
libpopt0/now 1.16-11 amd64 [installed,local]
libpq5/now 12.4-1.pgdg18.04+1 amd64 [installed,local]
libprocps6/now 2:3.3.12-3ubuntu1.2 amd64 [installed,local]
libpsl5/now 0.19.1-5build1 amd64 [installed,local]
libpython-stdlib/now 2.7.15~rc1-1 amd64 [installed,local]
libpython2.7-minimal/now 2.7.17-1~18.04ubuntu1.1 amd64 [installed,local]
libpython2.7-stdlib/now 2.7.17-1~18.04ubuntu1.1 amd64 [installed,local]
libpython3-stdlib/now 3.6.7-1~18.04 amd64 [installed,local]
libpython3.6-minimal/now 3.6.9-1~18.04ubuntu1.1 amd64 [installed,local]
libpython3.6-stdlib/now 3.6.9-1~18.04ubuntu1.1 amd64 [installed,local]
libquadmath0/now 8.4.0-1ubuntu1~18.04 amd64 [installed,local]
librabbitmq4/now 0.8.0-1ubuntu0.18.04.2 amd64 [installed,local]
libreadline7/now 7.0-3 amd64 [installed,local]
libroken18-heimdal/now 7.5.0+dfsg-1 amd64 [installed,local]
librsvg2-2/now 2.40.20-2ubuntu0.2 amd64 [installed,local]
librsvg2-common/now 2.40.20-2ubuntu0.2 amd64 [installed,local]
librtmp1/now 2.4+20151223.gitfa8646d.1-1 amd64 [installed,local]
libruby2.5/now 2.5.1-1ubuntu1.6 amd64 [installed,local]
libsasl2-2/now 2.1.27~101-g0780600+dfsg-3ubuntu2.1 amd64 [installed,local]
libsasl2-modules/now 2.1.27~101-g0780600+dfsg-3ubuntu2.1 amd64 [installed,local]
libsasl2-modules-db/now 2.1.27~101-g0780600+dfsg-3ubuntu2.1 amd64 [installed,local]
libseccomp2/now 2.4.3-1ubuntu3.18.04.3 amd64 [installed,local]
libselinux1/now 2.7-2build2 amd64 [installed,local]
libsemanage-common/now 2.7-2build2 all [installed,local]
libsemanage1/now 2.7-2build2 amd64 [installed,local]
libsepol1/now 2.7-1 amd64 [installed,local]
libsmartcols1/now 2.31.1-0.4ubuntu3.7 amd64 [installed,local]
libsodium23/now 1.0.16-2 amd64 [installed,local]
libsqlite3-0/now 3.22.0-1ubuntu0.4 amd64 [installed,local]
libsqlite3-dev/now 3.22.0-1ubuntu0.4 amd64 [installed,local]
libss2/now 1.44.1-1ubuntu1.3 amd64 [installed,local]
libssl1.0.0/now 1.0.2n-1ubuntu5.4 amd64 [installed,local]
libssl1.1/now 1.1.1-1ubuntu2.1~18.04.6 amd64 [installed,local]
libstdc++6/now 8.4.0-1ubuntu1~18.04 amd64 [installed,local]
libsystemd0/now 237-3ubuntu10.42 amd64 [installed,local]
libtasn1-6/now 4.13-2 amd64 [installed,local]
libthai-data/now 0.1.27-2 all [installed,local]
libthai0/now 0.1.27-2 amd64 [installed,local]
libtiff5/now 4.0.9-5ubuntu0.3 amd64 [installed,local]
libtinfo5/now 6.1-1ubuntu1.18.04 amd64 [installed,local]
libtsan0/now 8.4.0-1ubuntu1~18.04 amd64 [installed,local]
libubsan0/now 7.5.0-3ubuntu1~18.04 amd64 [installed,local]
libudev1/now 237-3ubuntu10.42 amd64 [installed,local]
libunistring2/now 0.9.9-0ubuntu2 amd64 [installed,local]
libuuid1/now 2.31.1-0.4ubuntu3.7 amd64 [installed,local]
libuv1/now 1.18.0-3 amd64 [installed,local]
libwebp6/now 0.6.1-2 amd64 [installed,local]
libwind0-heimdal/now 7.5.0+dfsg-1 amd64 [installed,local]
libwmf0.2-7/now 0.2.8.4-12 amd64 [installed,local]
libwrap0/now 7.6.q-27 amd64 [installed,local]
libx11-6/now 2:1.6.4-3ubuntu0.3 amd64 [installed,local]
libx11-data/now 2:1.6.4-3ubuntu0.3 all [installed,local]
libxau6/now 1:1.0.8-1ubuntu1 amd64 [installed,local]
libxcb-render0/now 1.13-2~ubuntu18.04 amd64 [installed,local]
libxcb-shm0/now 1.13-2~ubuntu18.04 amd64 [installed,local]
libxcb1/now 1.13-2~ubuntu18.04 amd64 [installed,local]
libxdmcp6/now 1:1.1.2-3 amd64 [installed,local]
libxext6/now 2:1.3.3-1 amd64 [installed,local]
libxml2/now 2.9.4+dfsg1-6.1ubuntu1.3 amd64 [installed,local]
libxpm4/now 1:3.5.12-1 amd64 [installed,local]
libxrender1/now 1:0.9.10-1 amd64 [installed,local]
libxslt1.1/now 1.1.29-5ubuntu0.2 amd64 [installed,local]
libyaml-0-2/now 0.1.7-2ubuntu3 amd64 [installed,local]
libzip4/now 1.1.2-1.1 amd64 [installed,local]
libzstd1/now 1.3.3+dfsg-2ubuntu1.1 amd64 [installed,local]
linux-libc-dev/now 4.15.0-118.119 amd64 [installed,local]
locales/now 2.27-3ubuntu1.2 all [installed,local]
login/now 1:4.5-1ubuntu2 amd64 [installed,local]
lsb-base/now 9.20170808ubuntu1 all [installed,local]
lsb-release/now 9.20170808ubuntu1 all [installed,local]
make/now 4.1-9.1ubuntu1 amd64 [installed,local]
mawk/now 1.3.3-17ubuntu3 amd64 [installed,local]
mime-support/now 3.60ubuntu1 all [installed,local]
mlock/now 8:2007f~dfsg-5ubuntu0.18.04.2 amd64 [installed,local]
mount/now 2.31.1-0.4ubuntu3.7 amd64 [installed,local]
mtools/now 4.0.18-2ubuntu1 amd64 [installed,local]
multiarch-support/now 2.27-3ubuntu1.2 amd64 [installed,local]
mysql-common/now 5.8+1.0.4 all [installed,local]
ncurses-base/now 6.1-1ubuntu1.18.04 all [installed,local]
ncurses-bin/now 6.1-1ubuntu1.18.04 amd64 [installed,local]
netbase/now 5.4 all [installed,local]
netcat-openbsd/now 1.187-1ubuntu0.1 amd64 [installed,local]
openssh-client/now 1:7.6p1-4ubuntu0.3 amd64 [installed,local]
openssh-server/now 1:7.6p1-4ubuntu0.3 amd64 [installed,local]
openssh-sftp-server/now 1:7.6p1-4ubuntu0.3 amd64 [installed,local]
openssl/now 1.1.1-1ubuntu2.1~18.04.6 amd64 [installed,local]
passwd/now 1:4.5-1ubuntu2 amd64 [installed,local]
patch/now 2.7.6-2ubuntu1.1 amd64 [installed,local]
perl/now 5.26.1-6ubuntu0.3 amd64 [installed,local]
perl-base/now 5.26.1-6ubuntu0.3 amd64 [installed,local]
perl-modules-5.26/now 5.26.1-6ubuntu0.3 all [installed,local]
pgdg-keyring/now 2018.2 all [installed,local]
pinentry-curses/now 1.1.0-1 amd64 [installed,local]
poppler-data/now 0.4.8-2 all [installed,local]
postgresql-client-12/now 12.4-1.pgdg18.04+1 amd64 [installed,local]
postgresql-client-common/now 216.pgdg18.04+1 all [installed,local]
procps/now 2:3.3.12-3ubuntu1.2 amd64 [installed,local]
python/now 2.7.15~rc1-1 amd64 [installed,local]
python-minimal/now 2.7.15~rc1-1 amd64 [installed,local]
python2.7/now 2.7.17-1~18.04ubuntu1.1 amd64 [installed,local]
python2.7-minimal/now 2.7.17-1~18.04ubuntu1.1 amd64 [installed,local]
python3/now 3.6.7-1~18.04 amd64 [installed,local]
python3-minimal/now 3.6.7-1~18.04 amd64 [installed,local]
python3.6/now 3.6.9-1~18.04ubuntu1.1 amd64 [installed,local]
python3.6-minimal/now 3.6.9-1~18.04ubuntu1.1 amd64 [installed,local]
rake/now 12.3.1-1ubuntu0.1 all [installed,local]
readline-common/now 7.0-3 all [installed,local]
rename/now 0.20-7 all [installed,local]
rsync/now 3.1.2-2.1ubuntu1.1 amd64 [installed,local]
ruby/now 1:2.5.1 amd64 [installed,local]
ruby-did-you-mean/now 1.2.0-2 all [installed,local]
ruby-minitest/now 5.10.3-1 all [installed,local]
ruby-net-telnet/now 0.1.1-2 all [installed,local]
ruby-power-assert/now 0.3.0-1 all [installed,local]
ruby-test-unit/now 3.2.5-1 all [installed,local]
ruby2.5/now 2.5.1-1ubuntu1.6 amd64 [installed,local]
rubygems-integration/now 1.11 all [installed,local]
sed/now 4.4-2 amd64 [installed,local]
sensible-utils/now 0.0.12 all [installed,local]
shared-mime-info/now 1.9-2 amd64 [installed,local]
socat/now 1.7.3.2-2ubuntu2 amd64 [installed,local]
stunnel4/now 3:5.44-1ubuntu3 amd64 [installed,local]
syslinux/now 3:6.03+dfsg1-2 amd64 [installed,local]
sysvinit-utils/now 2.88dsf-59.10ubuntu1 amd64 [installed,local]
tar/now 1.29b-2ubuntu0.1 amd64 [installed,local]
telnet/now 0.17-41 amd64 [installed,local]
tzdata/now 2020a-0ubuntu0.18.04 all [installed,local]
ubuntu-keyring/now 2018.09.18.1~18.04.0 all [installed,local]
ucf/now 3.0038 all [installed,local]
unzip/now 6.0-21ubuntu1 amd64 [installed,local]
util-linux/now 2.31.1-0.4ubuntu3.7 amd64 [installed,local]
wget/now 1.19.4-1ubuntu2.2 amd64 [installed,local]
xz-utils/now 5.2.2-1.3 amd64 [installed,local]
zip/now 3.0-11build1 amd64 [installed,local]
zlib1g/now 1:1.2.11.dfsg-0ubuntu2 amd64 [installed,local]
$ ls /usr/bin
2to3-2.7 faillog lsmem pphs strings
'[' fallocate lsns pr strip
addpart fc-cache lspgpot prename stunnel
addr2line fc-cat lz print stunnel3
amuFormat.sh fc-list lzcat printafm stunnel4
animate fc-match lzcmp printenv sum
animate-im6 fc-pattern lzdiff printf symcryptrun
animate-im6.q16 fc-query lzegrep prlimit syslinux
apt fc-scan lzfgrep procan tabs
apt-cache fc-validate lzgrep prove tac
apt-cdrom filan lzless ps2ascii tail
apt-config file lzma ps2epsi taskset
apt-extracttemplates file-rename lzmainfo ps2pdf tee
apt-ftparchive find lzmore ps2pdf12 telnet
apt-get flock make ps2pdf13 telnet.netkit
apt-key fmt make-first-existing-target ps2pdf14 test
apt-mark fold mattrib ps2pdfwr tgz
apt-sortpkgs free mawk ps2ps tic
ar funzip mbadblocks ps2ps2 timeout
arch gcc mcat ps2txt tload
as gcc-7 mcd psql toe
awk gcc-ar mcheck ptar top
b2sum gcc-ar-7 mclasserase ptardiff touch
base32 gcc-nm mcomp ptargrep tput
base64 gcc-nm-7 mcookie ptx tr
basename gcc-ranlib mcopy pwdx tracepath
bashbug gcc-ranlib-7 md5sum py3clean traceroute6
c++filt gcov md5sum.textutils py3compile traceroute6.iputils
c89 gcov-7 mdel py3versions truncate
c89-gcc gcov-dump mdeltree pyclean tset
c99 gcov-dump-7 mdig pycompile tsort
c99-gcc gcov-tool mdir pydoc tty
c_rehash gcov-tool-7 mdu pydoc2.7 tzselect
captoinfo gem mesg pydoc3 ucf
catchsegv gem2.5 mformat pydoc3.6 ucfq
cautious-launcher gencat migrate-pubring-from-classic-gpg pygettext ucfr
cc getconf minfo pygettext2.7 unexpand
chage getent mkfifo pygettext3 uniq
chattr getopt mkmanifest pygettext3.6 unlink
chcon ghostscript mlabel python unlzma
chfn git mlock python2 unshare
chrt git-receive-pack mmd python2.7 unxz
chsh git-shell mmount python3 unzip
cksum git-upload-archive mmove python3.6 unzipsfx
clear git-upload-pack mogrify python3.6m update-alternatives
clear_console gold mogrify-im6 python3m update-mime-database
clusterdb gpasswd mogrify-im6.q16 pyversions uptime
cmp gpg montage rake users
comm gpg-agent montage-im6 ranlib utmpdump
compare gpg-connect-agent montage-im6.q16 rcp uz
compare-im6 gpg-wks-server mpartition rdma vacuumdb
compare-im6.q16 gpg-zip mrd rdoc vacuumlo
compose gpgconf mren rdoc2.5 vmstat
composite gpgparsemail mshortname readelf w
composite-im6 gpgsm mshowfat realpath w.procps
composite-im6.q16 gpgsplit mtools reindexdb wall
conjure gpgv mtoolstest rename watch
conjure-im6 gprof mtrace rename.ul watchgnupg
conjure-im6.q16 groups mtype renice wc
convert gs mxtar reset wget
convert-im6 gsbj mzip resizepart whereis
convert-im6.q16 gsdj namei rev which
corelist gsdj500 nawk rgrep who
cpan gslj newgrp ri whoami
cpan5.26-x86_64-linux-gnu gslp nice ri2.5 x86_64
cpp gsnd nl rlogin x86_64-linux-gnu-addr2line
cpp-7 h2ph nm routef x86_64-linux-gnu-ar
createdb h2xs nohup routel x86_64-linux-gnu-as
createlang head nproc rpcgen x86_64-linux-gnu-c++filt
createuser host nsenter rsh x86_64-linux-gnu-cpp
csplit hostid nslookup rsync x86_64-linux-gnu-cpp-7
ctstat i386 nstat rtstat x86_64-linux-gnu-dwp
curl iconv nsupdate ruby x86_64-linux-gnu-elfedit
cut id numfmt ruby2.5 x86_64-linux-gnu-gcc
deb-systemd-helper identify objcopy run-mailcap x86_64-linux-gnu-gcc-7
deb-systemd-invoke identify-im6 objdump runcon x86_64-linux-gnu-gcc-ar
debconf identify-im6.q16 od savelog x86_64-linux-gnu-gcc-ar-7
debconf-apt-progress import openssl scp x86_64-linux-gnu-gcc-nm
debconf-communicate import-im6 pager script x86_64-linux-gnu-gcc-nm-7
debconf-copydb import-im6.q16 partx scriptreplay x86_64-linux-gnu-gcc-ranlib
debconf-escape infocmp passwd sdiff x86_64-linux-gnu-gcc-ranlib-7
debconf-set-selections infotocap paste see x86_64-linux-gnu-gcov
debconf-show install patch select-editor x86_64-linux-gnu-gcov-7
delpart instmodsh pathchk sensible-browser x86_64-linux-gnu-gcov-dump
delv ionice pdb sensible-editor x86_64-linux-gnu-gcov-dump-7
dh_python2 ipcmk pdb2.7 sensible-pager x86_64-linux-gnu-gcov-tool
diff ipcrm pdb3 seq x86_64-linux-gnu-gcov-tool-7
diff3 ipcs pdb3.6 setarch x86_64-linux-gnu-gold
dig irb pdf2dsc setsid x86_64-linux-gnu-gprof
dircolors irb2.5 pdf2ps setterm x86_64-linux-gnu-ld
dirmngr ischroot perl sftp x86_64-linux-gnu-ld.bfd
dirmngr-client join perl5.26-x86_64-linux-gnu sg x86_64-linux-gnu-ld.gold
dirname json_pp perl5.26.1 sha1sum x86_64-linux-gnu-nm
display kbxutil perlbug sha224sum x86_64-linux-gnu-objcopy
display-im6 last perldoc sha256sum x86_64-linux-gnu-objdump
display-im6.q16 lastb perlivp sha384sum x86_64-linux-gnu-ranlib
dpkg lastlog perlthanks sha512sum x86_64-linux-gnu-readelf
dpkg-deb lcf pf2afm shasum x86_64-linux-gnu-size
dpkg-divert ld pfbtopfa shred x86_64-linux-gnu-strings
dpkg-maintscript-helper ld.bfd pg_basebackup shuf x86_64-linux-gnu-strip
dpkg-query ld.gold pg_dump size xargs
dpkg-split ldd pg_dumpall skill xsubpp
dpkg-statoverride less pg_isready slabtop xz
dpkg-trigger lessecho pg_receivewal slogin xzcat
dropdb lessfile pg_receivexlog snice xzcmp
droplang lesskey pg_recvlogical socat xzdiff
dropuser lesspipe pg_restore sort xzegrep
du libnetcfg pgbench sotruss xzfgrep
dvipdf link pgrep splain xzgrep
dwp linux32 piconv split xzless
edit linux64 pinentry sprof xzmore
editor lnstat pinentry-curses ssh yes
elfedit locale pinky ssh-add zdump
enc2xs locale-check pkill ssh-agent zip
encguess localedef pl2pm ssh-argv0 zipcloak
env logger pldd ssh-copy-id zipdetails
eps2eps logname pmap ssh-keygen zipgrep
erb lsattr pod2html ssh-keyscan zipinfo
erb2.5 lsb_release pod2man stat zipnote
expand lscpu pod2text stdbuf zipsplit
expiry lsipc pod2usage stream
expr lslocks podchecker stream-im6
factor lslogins podselect stream-im6.q16
Despite libpython3.6 being installed with Ubuntu, running python --version returns 3.8.5. Here's why:
$ python --version
Python 3.8.5
$ which python
/workspace/.heroku/python/bin/python
$ ls -l /workspace/.heroku/python/bin
total 20423
lrwxrwxrwx 1 apps apps 8 Jan 1 1980 2to3 -> 2to3-3.8
-rwxr-xr-x 1 apps apps 110 Jan 1 1980 2to3-3.8
-rwxr-xr-x 1 apps apps 224 Jan 1 1980 datasette
-rwxr-xr-x 1 apps apps 244 Jan 1 1980 easy_install
-rwxr-xr-x 1 apps apps 244 Jan 1 1980 easy_install-3.8
-rwxr-xr-x 1 apps apps 223 Jan 1 1980 hupper
lrwxrwxrwx 1 apps apps 7 Jan 1 1980 idle3 -> idle3.8
-rwxr-xr-x 1 apps apps 108 Jan 1 1980 idle3.8
-rwxr-xr-x 1 apps apps 5289 Jan 1 1980 pint-convert
-rwxr-xr-x 1 apps apps 235 Jan 1 1980 pip
-rwxr-xr-x 1 apps apps 235 Jan 1 1980 pip3
-rwxr-xr-x 1 apps apps 235 Jan 1 1980 pip3.8
lrwxrwxrwx 1 apps apps 8 Jan 1 1980 pydoc3 -> pydoc3.8
-rwxr-xr-x 1 apps apps 93 Jan 1 1980 pydoc3.8
lrwxrwxrwx 1 apps apps 9 Jan 1 1980 python -> python3.8
lrwxrwxrwx 1 apps apps 9 Jan 1 1980 python3 -> python3.8
lrwxrwxrwx 1 apps apps 16 Jan 1 1980 python3-config -> python3.8-config
-rwxr-xr-x 1 apps apps 18541816 Jan 1 1980 python3.8
-rwxr-xr-x 1 apps apps 3096 Jan 1 1980 python3.8-config
-rwxr-xr-x 1 apps apps 1103280 Jan 1 1980 sqldiff
-rwxr-xr-x 1 apps apps 1260976 Jan 1 1980 sqlite3
-rwxr-xr-x 1 apps apps 225 Jan 1 1980 uvicorn
-rwxr-xr-x 1 apps apps 222 Jan 1 1980 wheel
I had datasette in my requirements.txt which is why the pint-convert, uvicorn, hupper and datasette binaries are in that folder.