Backport PR #37039: CI: move py39 build to conda #33948 (#38059)

Co-authored-by: Fangchen Li <fangchen.li@outlook.com>

Author: simonjayhawkins

.travis.yml

@@ -29,14 +29,6 @@ matrix:
   fast_finish: true
 
   include:
-    # In allowed failures
-    - dist: bionic
-      python: 3.9-dev
-      env:
-        - JOB="3.9-dev" PATTERN="(not slow and not network and not clipboard)"
-    - env:
-        - JOB="3.8" ENV_FILE="ci/deps/travis-38.yaml" PATTERN="(not slow and not network and not clipboard)"
-
     - env:
         - JOB="3.7" ENV_FILE="ci/deps/travis-37.yaml" PATTERN="(not slow and not network and not clipboard)"
 
@@ -92,7 +84,7 @@ install:
 script:
   - echo "script start"
   - echo "$JOB"
-  - if [ "$JOB" != "3.9-dev" ]; then source activate pandas-dev; fi
+  - source activate pandas-dev
   - ci/run_tests.sh
 
 after_script:

ci/azure/posix.yml

@@ -65,6 +65,11 @@ jobs:
           PANDAS_TESTING_MODE: "deprecate"
           EXTRA_APT: "xsel"
 
+        py39:
+          ENV_FILE: ci/deps/azure-39.yaml
+          CONDA_PY: "39"
+          PATTERN: "not slow and not network and not clipboard"
+
   steps:
     - script: |
         if [ "$(uname)" == "Linux" ]; then

ci/build39.sh

@@ -0,0 +1,17 @@
+name: pandas-dev
+channels:
+  - conda-forge
+dependencies:
+  - python=3.9.*
+
+  # tools
+  - cython>=0.29.21
+  - pytest>=5.0.1
+  - pytest-xdist>=1.21
+  - hypothesis>=3.58.0
+  - pytest-azurepipelines
+
+  # pandas dependencies
+  - numpy
+  - python-dateutil
+  - pytz

ci/deps/azure-39.yaml

@@ -1,10 +1,5 @@
 #!/bin/bash -e
 
-if [ "$JOB" == "3.9-dev" ]; then
-    /bin/bash ci/build39.sh
-    exit 0
-fi
-
 # edit the locale file if needed
 if [[ "$(uname)" == "Linux" && -n "$LC_ALL" ]]; then
     echo "Adding locale to the first line of pandas/__init__.py"