pyqt5-math-widget

A PyQt5 library for rendering and interactively editing mathematical formulas. No LaTeX engine required — everything is rendered natively via QPainter.

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Installation

pip install pyqt5-math-widget

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Widgets

Class	Purpose
MathView	Read-only formula renderer
MathEditor	Interactive formula editor with toolbar
MathDialog	Modal dialog wrapping MathEditor

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MathView — read-only renderer

Basic usage

from pyqt5_math_widget import MathView, FracNode, TextNode, SqrtNode

view = MathView()
view.set_node(FracNode(TextNode("1"), SqrtNode(TextNode("x"))))
layout.addWidget(view)

From a FormulaModel

from pyqt5_math_widget import MathView, FormulaModel

model = FormulaModel()
model.insert_frac()
model.insert_greek("pi")

view = MathView.from_model(model)

API

view.set_node(node)           # Set formula from a FormulaNode
view.set_model(model)         # Attach a FormulaModel
view.set_text("sin(x)")       # Set from plain text
view.set_zoom(1.5)            # Scale factor (default 1.0)
view.zoom()                   # -> float
view.set_background(color)    # QColor fill
view.set_transparent(True)    # Transparent background
view.set_padding(16, 12)      # Horizontal, vertical padding in px
view.set_foreground(color)    # Global text colour
view.to_pixmap(scale=2.0)     # -> QPixmap (for export/saving)
view.to_latex()               # -> str
view.to_sympy()               # -> str
view.to_text()                # -> str
view.model()                  # -> FormulaModel

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MathEditor — interactive editor

Basic usage

from pyqt5_math_widget import MathEditor

editor = MathEditor()
editor.formula_changed.connect(lambda s: print("sympy:", s))
editor.latex_changed.connect(lambda s: print("latex:", s))
layout.addWidget(editor)

Constructor parameters

MathEditor(
    parent=None,
    show_toolbar=True,          # Show button toolbar below canvas
    toolbar_groups=None,        # List of group names to show (see below)
    zoom=1.0,                   # Initial zoom level
    readonly=False,             # Disable editing
)

Toolbar groups

Pass a subset of these strings to toolbar_groups:

Group	Contents
"struct"	fraction, sqrt, power, subscript, integral, sum, product, limit, matrix, ...
"operators"	+, -, ·, ×, =, ≠, ≤, ≥, ±, ≈, ∂, ∇, ∈, ∀, →, ...
"greek"	α β γ δ ε θ λ μ ν π ρ σ τ φ ψ ω Σ Π Γ Δ Θ Ω ∞ ...
"functions"	sin cos tan arcsin log ln exp max min det tr ...
"edit"	Delete, Clear, ← →, Undo, Redo

editor.set_toolbar_groups(["struct", "greek", "edit"])

Programmatic insertion API

editor.insert_frac()                   # Fraction a/b
editor.insert_sqrt(nth=False)          # Square root
editor.insert_sqrt(nth=True)           # Nth root
editor.insert_power(wrap_current=True) # Superscript
editor.insert_subscript()              # Subscript
editor.insert_power_sub()              # Combined x^n_m
editor.insert_parens("(", ")")         # Parentheses (any bracket pair)
editor.insert_parens("[", "]")         # Square brackets
editor.insert_abs()                    # |x|
editor.insert_integral(definite=True)  # Definite integral
editor.insert_integral(definite=False) # Indefinite integral
editor.insert_sum(with_limits=True)    # Sum Σ
editor.insert_product(with_limits=True)# Product Π
editor.insert_limit()                  # lim
editor.insert_matrix(2, 2, "(")        # 2x2 matrix with round brackets
editor.insert_matrix(3, 3, "[")        # 3x3 matrix with square brackets
editor.insert_overline()               # Overline
editor.insert_underline()              # Underline
editor.insert_func("sin")             # sin(...) function
editor.insert_greek("alpha")          # α
editor.insert_operator("->")          # →
editor.insert_text("x", italic=True)  # Plain character
editor.insert_node(my_node)           # Raw FormulaNode

Editing control

editor.delete_at_cursor()    # Delete at cursor (Backspace)
editor.clear()               # Clear entire formula
editor.undo()                # Ctrl+Z
editor.redo()                # Ctrl+Y
editor.can_undo()            # -> bool
editor.can_redo()            # -> bool
editor.cursor_left()         # Move cursor left
editor.cursor_right()        # Move cursor right

Output

editor.to_sympy()    # "integrate(sin(x), x)"
editor.to_latex()    # r"\int \sin(x)\,dx"
editor.to_text()     # "integrate(sin(x), x)"
editor.to_pixmap(scale=2.0)   # -> QPixmap

Display control

editor.set_zoom(1.5)
editor.set_readonly(True)
editor.set_toolbar_visible(False)
editor.model()                # -> FormulaModel for direct access
editor.set_model(model)       # Replace model

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MathDialog — modal dialog

from pyqt5_math_widget import MathDialog
from PyQt5.QtWidgets import QDialog

dlg = MathDialog(
    parent=self,
    title="Insert Formula",
    initial_text="sin(x)",
    toolbar_groups=["struct", "greek", "edit"],
    show_output=True,
    zoom=1.1,
)
if dlg.exec_() == QDialog.Accepted:
    print(dlg.result_sympy())
    print(dlg.result_latex())
    print(dlg.result_text())

Connect the signal without blocking:

dlg = MathDialog(parent=self)
dlg.accepted_formula.connect(lambda s: print("inserted:", s))
dlg.show()

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FormulaModel — programmatic tree manipulation

from pyqt5_math_widget import FormulaModel

model = FormulaModel()
model.insert_frac()
model.insert_text("x")
model.move_right()
model.insert_text("2")

print(model.to_sympy())  # (x) / (2)
print(model.to_latex())  # \frac{x}{2}

model.undo()
model.redo()
model.clear()

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Formula node tree

Build a formula tree and display it statically:

from pyqt5_math_widget import (
    MathView, SeqNode, TextNode, FracNode, SqrtNode,
    PowerNode, IntegralNode, SumProdNode, MatrixNode,
    ParenNode, AbsNode,
)

root = SeqNode([
    TextNode("E"),
    TextNode("="),
    FracNode(
        TextNode("m"),
        SqrtNode(SeqNode([TextNode("1"), TextNode("-"), PowerNode(TextNode("v"), TextNode("2"))])),
    ),
])

view = MathView()
view.set_node(root)

Available node types

Class	Description
TextNode(text, size, italic, bold, color)	Text / symbol
PlaceholderNode(size)	Editable placeholder
SeqNode(children)	Horizontal sequence
FracNode(num, den)	Fraction
SqrtNode(body, index=None)	Square / nth root
PowerNode(base, exp)	Superscript
SubNode(base, sub)	Subscript
PowerSubNode(base, exp, sub)	Combined sup+sub
ParenNode(body, left, right)	Scalable brackets
AbsNode(body)	Absolute value
IntegralNode(body, var, lower, upper)	Integral
SumProdNode(kind, body, var, lower, upper)	Sum / Product
LimitNode(body, var, approach, direction)	Limit
MatrixNode(rows, left, right)	Matrix
OverlineNode(body)	Overline
UnderlineNode(body)	Underline

Each node implements:

node.to_sympy()   # SymPy expression string
node.to_latex()   # LaTeX string
node.to_text()    # Plain text
node.measure(painter)  # -> RenderMetrics
node.draw(painter, x, y, hits, selected, cursor_id)
node.collect_ids()     # -> List[int]
node.clone()           # deep copy

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Constants and maps

from pyqt5_math_widget import GREEK_MAP, OPERATOR_MAP

GREEK_MAP["alpha"]   # -> "α"
OPERATOR_MAP["->"]   # -> "→"

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Integration

from pyqt5_math_widget import MathDialog
from PyQt5.QtWidgets import QPushButton

btn = QPushButton("\u03A3")
btn.clicked.connect(lambda: self._open_formula_editor())

def _open_formula_editor(self):
    dlg = MathDialog(initial_text=self._input.text(), parent=self.window())
    if dlg.exec_():
        self._input.setText(dlg.result_sympy())

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License

MIT