Bug fixes, added some units, improved printing

README.md

@@ -27,7 +27,6 @@ Here are a few useful things to keep in mind when using `ipycalc`:
 * Square roots can be displayed using `sqrt`.
 * Prime characters can be displayed using `^prime`.
 * If a line gets too long for printing, you can add a line break to the description, equation, or reference by inserting `\\`.
-* US units are built in via `Pint`. Basic support is available for some more common metric units.
-* `ipycalc` has a built in `nbconvert` template called `ipycalc` that works just like the `webpdf` template, except it fixes the the bad margins in the `webpdf` template.
+* `ipycalc` has a built in `nbconvert` template called `ipycalc` that works just like the `webpdf` template, except it fixes the the bad margins in the `webpdf` template, reduces the print size to 85% to fit more calcs on a single sheet, and avoids page breaks right after headers.
 
 IPycalc is still in its infancy. I'm sure there are bugs, so be cautious and use your head. A special thanks to @connorferster for `handcalcs` which inspired this project: https://github.com/connorferster/handcalcs

ipycalc/__init__.py

@@ -1,15 +1,32 @@
 import os
 from nbconvert.exporters import WebPDFExporter
+from nbconvert.preprocessors import TagRemovePreprocessor
 
 class ipycalcExporter(WebPDFExporter):
     """
     A custom PDF exporter for ipycalc.
     """
 
+    # This is the name of the folder containing the template in `ipycalc`
     custom_template_name = 'nbconvert_template'
+
+    # This is the directory where ipycalc is installed on the user's machine
     pkg_dir = os.path.dirname(__file__)
+
+    # This is the location where the `ipycalc` template is installed on the user's machine
     template_dir = os.path.join(pkg_dir, custom_template_name)
 
+    def __init__(self):
+
+        # Run the WebPDFExporter constructor
+        super().__init__()
+
+        # Set up preprocessors
+        trp = TagRemovePreprocessor()
+        trp.remove_cell_tags=['hide_cell']
+        trp.remove_input_tags=['hide_input']
+        self.register_preprocessor(trp, enabled=True)
+
     @property
     def _extra_template_basedirs(self):
         return super()._default_extra_template_basedirs() + [self.template_dir]

ipycalc/calc.py

@@ -28,6 +28,8 @@
 lbf = ureg.force_pound
 lbm = ureg.pound
 kip = ureg.kip
+ton = ureg.ton
+tonf = ureg.force_ton
 plf = ureg.plf
 klf = ureg.klf
 psi = ureg.force_pound/ureg.inch**2
@@ -55,6 +57,8 @@
 km = ureg.kilometer
 N = ureg.newton
 kN = ureg.kilonewton
+ton = ureg.metric_ton
+tonnef = ureg.force_metric_ton
 Pa = ureg.pascal
 kPa = ureg.kilopascal
 MPa = ureg.megapascal
@@ -116,6 +120,8 @@ def sync_namespaces(local_ns):
     local_ns['lbm'] = ureg.pound
     local_ns['kip'] = ureg.kip
     local_ns['k']= ureg.kip
+    local_ns['ton'] = ureg.ton
+    local_ns['tonf'] = ureg.force_ton
     local_ns['plf'] = ureg.plf
     local_ns['klf'] = ureg.klf
     local_ns['psi'] = ureg.force_pound/ureg.inch**2
@@ -143,10 +149,13 @@ def sync_namespaces(local_ns):
     local_ns['km'] = ureg.kilometer
     local_ns['N'] = ureg.newton
     local_ns['kN'] = ureg.kilonewton
+    local_ns['kg'] = ureg.kilogram
     local_ns['Pa'] = ureg.pascal
     local_ns['kPa'] = ureg.kilopascal
     local_ns['MPa'] = ureg.megapascal
     local_ns['GPa'] = ureg.gigapascal
+    local_ns['tonne'] = ureg.metric_ton
+    local_ns['tonnef'] = ureg.force_metric_ton
 
     # Provide the IPython console with access to the `funit` method
     local_ns['funit'] = funit
@@ -156,8 +165,7 @@ def process_line(calc_line, local_ns):
 
     # Ampersand symbols will mess with latex table formatting unless they have a `\` in front of
     # them
-    if '&' in calc_line:
-        calc_line = calc_line.replace('&', '\&')
+    calc_line = calc_line.replace('&', '\&')
 
     # Break up the line into components: `description`, `variable`, `equation`, `value` and `reference`
     if '#' in calc_line:
@@ -197,8 +205,8 @@ def process_line(calc_line, local_ns):
     variable = variable.replace('^prime', '_prime')
 
     # Make a latex copy of the equation and variable before we switch out square root symbols
-    latex_variable = to_latex(variable)
-    latex_equation = to_latex(equation)
+    latex_variable = python_to_latex(variable)
+    latex_equation = python_to_latex(equation)
 
     # `Pint` prefers exponents to the 1/2 power instead of square roots
     equation = alt_sqrt(equation)
@@ -334,7 +342,14 @@ def process_line(calc_line, local_ns):
     return latex_text
 
 #%%
-def to_latex(text):
+def python_to_latex(text):
+    """Converts python equations to latex equations
+
+    :param text: Python text to be converted to latex.
+    :type text: str
+    :return: Latex text
+    :rtype: str
+    """
 
     # Change spaces we want to keep to the '@' symbol temporarily
     text = text.replace(' if ', '@if@')
@@ -343,6 +358,9 @@ def to_latex(text):
     # Add any prime symbols back in
     text = text.replace('_prime', '^{\\prime}')
 
+    # Switch out Python's exponent symbols for Latex's
+    text = text.replace('**', '^')
+
     # Add brackets to superscripts and subscripts if they are missing
     text = sscript_curly('^', text)
     text = sscript_curly('_', text)
@@ -375,8 +393,7 @@ def to_latex(text):
     # Take care of any lower case greek psi characters. This is necessary because 'psi' is also a unit
     text = text.replace('grpsi', '\\psi')
 
-    # Switch out Python's exponent symbols for Latex's
-    text = text.replace('**', '^')
+    #
 
     # Convert common functions to latex
     text = text.replace('sin', '\\sin')
@@ -395,7 +412,7 @@ def to_latex(text):
     text = text.replace('*', ' \\cdot{}')
     text = text.replace('sqrt', '\\sqrt')
 
-    # Change any parentheses to brackets 
+    # Change any parentheses to brackets for `sqrt`, `^`, and `_`
     text = curly_brackets('sqrt', text)
     text = curly_brackets('^', text)
     text = curly_brackets('_', text)
@@ -496,7 +513,7 @@ def sscript_curly(symbol, text):
     term_list = []
     for i, char in enumerate(text):
 
-        # Find any lone symbols
+        # Find any instances of `symbol` that have not already been formatted properly
         if char == symbol and text[i:i+2] != symbol + '(' and text[i:i+2] != symbol + '{':
 
             # Initialize the term after the symbol

setup.py

@@ -5,7 +5,7 @@
 
 setuptools.setup(
     name="ipycalc",
-    version="0.0.48",
+    version="0.0.49",
     author="D. Craig Brinck, PE, SE",
     author_email="[email protected]",
     description="Clean looking engineering calculations for IPython",