From 1a1ddee05ee2a7d89efda8c1ab12a9c7be6b01d7 Mon Sep 17 00:00:00 2001
From: Marco Gorelli <m.gorelli@ws-1808.seri.co.uk>
Date: Thu, 19 Dec 2019 16:36:58 +0000
Subject: [PATCH] :sparkles: Add to_markdown method

---
 doc/source/whatsnew/v1.0.0.rst              |  1 +
 environment.yml                             |  1 +
 pandas/core/frame.py                        | 24 +++++++++++++++++++++
 pandas/tests/io/formats/test_to_markdown.py | 12 +++++++++++
 pandas/util/_test_decorators.py             |  7 ++++++
 requirements-dev.txt                        |  1 +
 6 files changed, 46 insertions(+)
 create mode 100644 pandas/tests/io/formats/test_to_markdown.py

diff --git a/doc/source/whatsnew/v1.0.0.rst b/doc/source/whatsnew/v1.0.0.rst
index a31db9712d5b84..1e3a672fd6180f 100644
--- a/doc/source/whatsnew/v1.0.0.rst
+++ b/doc/source/whatsnew/v1.0.0.rst
@@ -207,6 +207,7 @@ Other enhancements
 - The ``partition_cols`` argument in :meth:`DataFrame.to_parquet` now accepts a string (:issue:`27117`)
 - :func:`to_parquet` now appropriately handles the ``schema`` argument for user defined schemas in the pyarrow engine. (:issue: `30270`)
 - DataFrame constructor preserve `ExtensionArray` dtype with `ExtensionArray` (:issue:`11363`)
+- :meth:`DataFrame.to_markdown` added (:issue:`11052`)
 
 
 Build Changes
diff --git a/environment.yml b/environment.yml
index 2b171d097a6937..674efe9d5f6dc7 100644
--- a/environment.yml
+++ b/environment.yml
@@ -72,6 +72,7 @@ dependencies:
   - matplotlib>=2.2.2  # pandas.plotting, Series.plot, DataFrame.plot
   - numexpr>=2.6.8
   - scipy>=1.1
+  - tabulate
 
   # optional for io
   - beautifulsoup4>=4.6.0  # pandas.read_html
diff --git a/pandas/core/frame.py b/pandas/core/frame.py
index 6f760e7ee4ca07..b1311a1b901af5 100644
--- a/pandas/core/frame.py
+++ b/pandas/core/frame.py
@@ -36,6 +36,7 @@
 from pandas._config import get_option
 
 from pandas._libs import algos as libalgos, lib
+from pandas.compat._optional import import_optional_dependency
 from pandas.compat.numpy import function as nv
 from pandas.util._decorators import (
     Appender,
@@ -1964,6 +1965,29 @@ def to_feather(self, path):
 
         to_feather(self, path)
 
+    def to_markdown(self):
+        """
+        Print a DataFrame in markdown-friendly format.
+
+        .. versionadded:: 1.0
+
+        Returns
+        -------
+        str
+            DataFrame in markdown-friendly format.
+
+        Examples
+        --------
+        >>> df = pd.DataFrame(data={'col1': [1, 2], 'col2': [3, 4]})
+        >>> print(df.to_markdown())
+        |    |   col1 |   col2 |
+        |---:|-------:|-------:|
+        |  0 |      1 |      3 |
+        |  1 |      2 |      4 |
+        """
+        tabulate = import_optional_dependency("tabulate")
+        return self.pipe(tabulate.tabulate, headers="keys", tablefmt="pipe")
+
     @deprecate_kwarg(old_arg_name="fname", new_arg_name="path")
     def to_parquet(
         self,
diff --git a/pandas/tests/io/formats/test_to_markdown.py b/pandas/tests/io/formats/test_to_markdown.py
new file mode 100644
index 00000000000000..bbbc5955956c75
--- /dev/null
+++ b/pandas/tests/io/formats/test_to_markdown.py
@@ -0,0 +1,12 @@
+import pandas.util._test_decorators as td
+
+import pandas as pd
+
+
+@td.skip_if_no_tabulate
+def test_to_markdown():
+    df = pd.DataFrame([1, 2, 3])
+    result = df.to_markdown()
+    assert (
+        result == "|    |   0 |\n|---:|----:|\n|  0 |   1 |\n|  1 |   2 |\n|  2 |   3 |"
+    )
diff --git a/pandas/util/_test_decorators.py b/pandas/util/_test_decorators.py
index 0e3ea25bf6fdb5..5192142118c17f 100644
--- a/pandas/util/_test_decorators.py
+++ b/pandas/util/_test_decorators.py
@@ -119,6 +119,10 @@ def _skip_if_no_scipy():
     )
 
 
+def _skip_if_no_tabulate():
+    return not safe_import("tabulate")
+
+
 def skip_if_installed(package: str) -> Callable:
     """
     Skip a test if a package is installed.
@@ -193,6 +197,9 @@ def skip_if_no(package: str, min_version: Optional[str] = None) -> Callable:
     not _USE_NUMEXPR,
     reason=f"numexpr enabled->{_USE_NUMEXPR}, " f"installed->{_NUMEXPR_INSTALLED}",
 )
+skip_if_no_tabulate = pytest.mark.skipif(
+    _skip_if_no_tabulate(), reason="Missing tabulate requirement"
+)
 
 
 def skip_if_np_lt(ver_str, reason=None, *args, **kwds):
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 5f67726a3e476d..6d75a975fd5b5a 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -55,6 +55,7 @@ openpyxl<=3.0.1
 pyarrow>=0.13.1
 pyqt5>=5.9.2
 tables>=3.4.2
+tabulate
 python-snappy
 s3fs
 sqlalchemy