J'avais implémenté un shell python en utilisant code.InteractiveConsolepour exécuter les commandes d'un projet. Ci-dessous est une version simplifiée, bien que toujours assez longue car j'avais écrit des liaisons pour des touches spéciales (comme Return, Tab ...) pour se comporter comme dans la console python. Il est possible d'ajouter plus de fonctionnalités telles que la saisie semi-automatique avec jedi et la mise en évidence de la syntaxe avec pygments.
L'idée principale est que j'utilise la push()méthode du code.InteractiveConsolepour exécuter les commandes. Cette méthode retourne Trues'il s'agit d'une commande partielle, par exemple def test(x):, et j'utilise cette rétroaction pour insérer une ...invite, sinon, la sortie est affichée et une nouvelle >>>invite est affichée. Je capture la sortie en utilisant contextlib.redirect_stdout.
Il y a aussi beaucoup de code impliquant des marques et comparant les index car j'empêche l'utilisateur d'insérer du texte dans des commandes précédemment exécutées. L'idée est que j'ai créé une marque «entrée» qui m'indique où se trouve le début de l'invite active et avec self.compare('insert', '<', 'input')je peux savoir quand l'utilisateur essaie d'insérer du texte au-dessus de l'invite active.
import tkinter as tk
import sys
import re
from code import InteractiveConsole
from contextlib import redirect_stderr, redirect_stdout
from io import StringIO
class History(list):
def __getitem__(self, index):
try:
return list.__getitem__(self, index)
except IndexError:
return
class TextConsole(tk.Text):
def __init__(self, master, **kw):
kw.setdefault('width', 50)
kw.setdefault('wrap', 'word')
kw.setdefault('prompt1', '>>> ')
kw.setdefault('prompt2', '... ')
banner = kw.pop('banner', 'Python %s\n' % sys.version)
self._prompt1 = kw.pop('prompt1')
self._prompt2 = kw.pop('prompt2')
tk.Text.__init__(self, master, **kw)
# --- history
self.history = History()
self._hist_item = 0
self._hist_match = ''
# --- initialization
self._console = InteractiveConsole() # python console to execute commands
self.insert('end', banner, 'banner')
self.prompt()
self.mark_set('input', 'insert')
self.mark_gravity('input', 'left')
# --- bindings
self.bind('<Control-Return>', self.on_ctrl_return)
self.bind('<Shift-Return>', self.on_shift_return)
self.bind('<KeyPress>', self.on_key_press)
self.bind('<KeyRelease>', self.on_key_release)
self.bind('<Tab>', self.on_tab)
self.bind('<Down>', self.on_down)
self.bind('<Up>', self.on_up)
self.bind('<Return>', self.on_return)
self.bind('<BackSpace>', self.on_backspace)
self.bind('<Control-c>', self.on_ctrl_c)
self.bind('<<Paste>>', self.on_paste)
def on_ctrl_c(self, event):
"""Copy selected code, removing prompts first"""
sel = self.tag_ranges('sel')
if sel:
txt = self.get('sel.first', 'sel.last').splitlines()
lines = []
for i, line in enumerate(txt):
if line.startswith(self._prompt1):
lines.append(line[len(self._prompt1):])
elif line.startswith(self._prompt2):
lines.append(line[len(self._prompt2):])
else:
lines.append(line)
self.clipboard_clear()
self.clipboard_append('\n'.join(lines))
return 'break'
def on_paste(self, event):
"""Paste commands"""
if self.compare('insert', '<', 'input'):
return "break"
sel = self.tag_ranges('sel')
if sel:
self.delete('sel.first', 'sel.last')
txt = self.clipboard_get()
self.insert("insert", txt)
self.insert_cmd(self.get("input", "end"))
return 'break'
def prompt(self, result=False):
"""Insert a prompt"""
if result:
self.insert('end', self._prompt2, 'prompt')
else:
self.insert('end', self._prompt1, 'prompt')
self.mark_set('input', 'end-1c')
def on_key_press(self, event):
"""Prevent text insertion in command history"""
if self.compare('insert', '<', 'input') and event.keysym not in ['Left', 'Right']:
self._hist_item = len(self.history)
self.mark_set('insert', 'input lineend')
if not event.char.isalnum():
return 'break'
def on_key_release(self, event):
"""Reset history scrolling"""
if self.compare('insert', '<', 'input') and event.keysym not in ['Left', 'Right']:
self._hist_item = len(self.history)
return 'break'
def on_up(self, event):
"""Handle up arrow key press"""
if self.compare('insert', '<', 'input'):
self.mark_set('insert', 'end')
return 'break'
elif self.index('input linestart') == self.index('insert linestart'):
# navigate history
line = self.get('input', 'insert')
self._hist_match = line
hist_item = self._hist_item
self._hist_item -= 1
item = self.history[self._hist_item]
while self._hist_item >= 0 and not item.startswith(line):
self._hist_item -= 1
item = self.history[self._hist_item]
if self._hist_item >= 0:
index = self.index('insert')
self.insert_cmd(item)
self.mark_set('insert', index)
else:
self._hist_item = hist_item
return 'break'
def on_down(self, event):
"""Handle down arrow key press"""
if self.compare('insert', '<', 'input'):
self.mark_set('insert', 'end')
return 'break'
elif self.compare('insert lineend', '==', 'end-1c'):
# navigate history
line = self._hist_match
self._hist_item += 1
item = self.history[self._hist_item]
while item is not None and not item.startswith(line):
self._hist_item += 1
item = self.history[self._hist_item]
if item is not None:
self.insert_cmd(item)
self.mark_set('insert', 'input+%ic' % len(self._hist_match))
else:
self._hist_item = len(self.history)
self.delete('input', 'end')
self.insert('insert', line)
return 'break'
def on_tab(self, event):
"""Handle tab key press"""
if self.compare('insert', '<', 'input'):
self.mark_set('insert', 'input lineend')
return "break"
# indent code
sel = self.tag_ranges('sel')
if sel:
start = str(self.index('sel.first'))
end = str(self.index('sel.last'))
start_line = int(start.split('.')[0])
end_line = int(end.split('.')[0]) + 1
for line in range(start_line, end_line):
self.insert('%i.0' % line, ' ')
else:
txt = self.get('insert-1c')
if not txt.isalnum() and txt != '.':
self.insert('insert', ' ')
return "break"
def on_shift_return(self, event):
"""Handle Shift+Return key press"""
if self.compare('insert', '<', 'input'):
self.mark_set('insert', 'input lineend')
return 'break'
else: # execute commands
self.mark_set('insert', 'end')
self.insert('insert', '\n')
self.insert('insert', self._prompt2, 'prompt')
self.eval_current(True)
def on_return(self, event=None):
"""Handle Return key press"""
if self.compare('insert', '<', 'input'):
self.mark_set('insert', 'input lineend')
return 'break'
else:
self.eval_current(True)
self.see('end')
return 'break'
def on_ctrl_return(self, event=None):
"""Handle Ctrl+Return key press"""
self.insert('insert', '\n' + self._prompt2, 'prompt')
return 'break'
def on_backspace(self, event):
"""Handle delete key press"""
if self.compare('insert', '<=', 'input'):
self.mark_set('insert', 'input lineend')
return 'break'
sel = self.tag_ranges('sel')
if sel:
self.delete('sel.first', 'sel.last')
else:
linestart = self.get('insert linestart', 'insert')
if re.search(r' $', linestart):
self.delete('insert-4c', 'insert')
else:
self.delete('insert-1c')
return 'break'
def insert_cmd(self, cmd):
"""Insert lines of code, adding prompts"""
input_index = self.index('input')
self.delete('input', 'end')
lines = cmd.splitlines()
if lines:
indent = len(re.search(r'^( )*', lines[0]).group())
self.insert('insert', lines[0][indent:])
for line in lines[1:]:
line = line[indent:]
self.insert('insert', '\n')
self.prompt(True)
self.insert('insert', line)
self.mark_set('input', input_index)
self.see('end')
def eval_current(self, auto_indent=False):
"""Evaluate code"""
index = self.index('input')
lines = self.get('input', 'insert lineend').splitlines() # commands to execute
self.mark_set('insert', 'insert lineend')
if lines: # there is code to execute
# remove prompts
lines = [lines[0].rstrip()] + [line[len(self._prompt2):].rstrip() for line in lines[1:]]
for i, l in enumerate(lines):
if l.endswith('?'):
lines[i] = 'help(%s)' % l[:-1]
cmds = '\n'.join(lines)
self.insert('insert', '\n')
out = StringIO() # command output
err = StringIO() # command error traceback
with redirect_stderr(err): # redirect error traceback to err
with redirect_stdout(out): # redirect command output
# execute commands in interactive console
res = self._console.push(cmds)
# if res is True, this is a partial command, e.g. 'def test():' and we need to wait for the rest of the code
errors = err.getvalue()
if errors: # there were errors during the execution
self.insert('end', errors) # display the traceback
self.mark_set('input', 'end')
self.see('end')
self.prompt() # insert new prompt
else:
output = out.getvalue() # get output
if output:
self.insert('end', output, 'output')
self.mark_set('input', 'end')
self.see('end')
if not res and self.compare('insert linestart', '>', 'insert'):
self.insert('insert', '\n')
self.prompt(res)
if auto_indent and lines:
# insert indentation similar to previous lines
indent = re.search(r'^( )*', lines[-1]).group()
line = lines[-1].strip()
if line and line[-1] == ':':
indent = indent + ' '
self.insert('insert', indent)
self.see('end')
if res:
self.mark_set('input', index)
self._console.resetbuffer() # clear buffer since the whole command will be retrieved from the text widget
elif lines:
self.history.append(lines) # add commands to history
self._hist_item = len(self.history)
out.close()
err.close()
else:
self.insert('insert', '\n')
self.prompt()
if __name__ == '__main__':
root = tk.Tk()
console = TextConsole(root)
console.pack(fill='both', expand=True)
root.mainloop()