ENH: add LaTeX math mode with parentheses

pandas/io/formats/style_render.py

@@ -1117,7 +1117,8 @@ def format(
  2 & \textbf{\$\%\#} \\
  \end{tabular}
 
- Using ``escape`` in 'latex-math' mode.
+ Applying ``escape`` in 'latex-math' mode. In the example below
+ we enter math mode using the charackter ``$``.
 
  >>> df = pd.DataFrame([[r"$\sum_{i=1}^{10} a_i$ a~b $\alpha \
  ... = \frac{\beta}{\zeta^2}$"], ["%#^ $ \$x^2 $"]])
@@ -1129,6 +1130,20 @@ def format(
  1 & \%\#\textasciicircum \space $ \$x^2 $ \\
  \end{tabular}
 
+ We can use the charackter ``\(`` to enter math mode and the charackter ``\)``
+ to close math mode.
+
+ >>> df = pd.DataFrame([[r"\(\sum_{i=1}^{10} a_i\) a~b \(\alpha \
+ ... = \frac{\beta}{\zeta^2}\)"], ["%#^ \( \$x^2 \)"]])
+ >>> df.style.format(escape="latex-math").to_latex()
+ ... # doctest: +SKIP
+ \begin{tabular}{ll}
+ & 0 \\
+ 0 & \(\sum_{i=1}^{10} a_i\) a\textasciitilde b \(\alpha
+ = \frac{\beta}{\zeta^2}\) \\
+ 1 & \%\#\textasciicircum \space \( \$x^2 \) \\
+ \end{tabular}
+
  Pandas defines a `number-format` pseudo CSS attribute instead of the `.format`
  method to create `to_excel` permissible formatting. Note that semi-colons are
  CSS protected characters but used as separators in Excel's format string.
@@ -2357,17 +2372,20 @@ def _escape_latex(s):
  .replace("~", "\\textasciitilde ")
  .replace("^ ", "^\\space ") # since \textasciicircum gobbles spaces
  .replace("^", "\\textasciicircum ")
+ .replace("ab2§=§8yz(", "\\( ")
+ .replace("ab2§=§8yz)", "\\) ")
  .replace("ab2§=§8yz", "\\textbackslash ")
  )
 
 
 def _escape_latex_math(s):
  r"""
- All characters between two characters ``$`` are preserved.
+ All characters in LaTeX math mode are preserved.
 
- The substrings in LaTeX math mode, which start with the character ``$``
- and end with ``$``, are preserved without escaping. Otherwise
- regular LaTeX escaping applies. See ``_escape_latex()``.
+ The substrings in LaTeX math mode, which either are surrounded
+ by two characters ``$`` or start with the character ``\(`` and end with ``\)``,
+ are preserved without escaping. Otherwise regular LaTeX escaping applies.
+ See ``_escape_latex()``.
 
  Parameters
  ----------
@@ -2379,16 +2397,37 @@ def _escape_latex_math(s):
  str :
  Escaped string
  """
- s = s.replace(r"\$", r"rt8§=§7wz")
- pattern = re.compile(r"\$.*?\$")
- pos = 0
- ps = pattern.search(s, pos)
- res = []
- while ps:
- res.append(_escape_latex(s[pos : ps.span()[0]]))
- res.append(ps.group())
- pos = ps.span()[1]
+
+ def _math_mode_with_dollar(s):
+ s = s.replace(r"\$", r"rt8§=§7wz")
+ pattern = re.compile(r"\$.*?\$")
+ pos = 0
  ps = pattern.search(s, pos)
+ res = []
+ while ps:
+ res.append(_escape_latex(s[pos : ps.span()[0]]))
+ res.append(ps.group())
+ pos = ps.span()[1]
+ ps = pattern.search(s, pos)
+
+ res.append(_escape_latex(s[pos : len(s)]))
+ return "".join(res).replace(r"rt8§=§7wz", r"\$")
+
+ def _math_mode_with_parentheses(s):
+ s = s.replace(r"\(", r"LEFT§=§6yzLEFT").replace(r"\)", r"RIGHTab5§=§RIGHT")
+ res = []
+ for item in re.split(r"LEFT§=§6yz|ab5§=§RIGHT", s):
+ if item.startswith("LEFT") and item.endswith("RIGHT"):
+ res.append(item.replace("LEFT", r"\(").replace("RIGHT", r"\)"))
+ else:
+ res.append(
+ _escape_latex(item).replace("LEFT", r"\(").replace("RIGHT", r"\)")
+ )
+ return "".join(res)
 
- res.append(_escape_latex(s[pos : len(s)]))
- return "".join(res).replace(r"rt8§=§7wz", r"\$")
+ if s.replace(r"\$", "ab").find(r"$") > -1:
+ return _math_mode_with_dollar(s)
+ elif s.find(r"\(") > -1:
+ return _math_mode_with_parentheses(s)
+ else:
+ return _escape_latex(s)

pandas/tests/io/formats/style/test_format.py

@@ -192,13 +192,22 @@ def test_format_escape_html(escape, exp):
  assert styler._translate(True, True)["head"][0][1]["display_value"] == f"&{exp}&"
 
 
-def test_format_escape_latex_math():
- chars = r"$\frac{1}{2} \$ x^2$ ~%#^"
- df = DataFrame([[chars]])
+@pytest.mark.parametrize(
+ "chars, expected",
+ [
+ (r"$\frac{1}{2} \$ x^2$ ", r"$\frac{1}{2} \$ x^2$ "),
+ (r"\(\frac{1}{2} \$ x^2\) ", r"\(\frac{1}{2} \$ x^2\) "),
+ (r"\)", r"\) "),
+ ],
+)
+def test_format_escape_latex_math(chars, expected):
+ df = DataFrame([["".join([chars, "~%#^"])]])
 
- expected = r"$\frac{1}{2} \$ x^2$ \textasciitilde \%\#\textasciicircum "
  s = df.style.format("{0}", escape="latex-math")
- assert expected == s._translate(True, True)["body"][0][1]["display_value"]
+ assert (
+ "".join([expected, r"\textasciitilde \%\#\textasciicircum "])
+ == s._translate(True, True)["body"][0][1]["display_value"]
+ )
 
 
 def test_format_escape_na_rep():