File Dialogs¶

emzed_gui provides four file-dialog helpers that wrap Qt's QFileDialog. All of them create a QApplication if none exists, so they can be called from a plain script without any Qt setup.

Every function returns None when the user cancels the dialog.

ask_for_directory¶

emzed_gui.ask_for_directory(start_at=None, caption="Choose Folder") -> str | None

Opens a folder-picker dialog. Returns the selected directory path as a string, or None on cancel.

import emzed_gui

folder = emzed_gui.ask_for_directory(start_at="/data/lcms")
if folder is not None:
    print(f"Selected: {folder}")

ask_for_single_file¶

emzed_gui.ask_for_single_file(
    start_at=None, extensions=None, caption="Open File"
) -> str | None

Opens a file-picker limited to one existing file. Pass extensions to restrict which file types are shown.

path = emzed_gui.ask_for_single_file(
    start_at="/data/lcms",
    extensions=["mzXML", "mzML"],
)
if path is not None:
    peakmap = emzed.io.load_peakmap(path)

ask_for_multiple_files¶

emzed_gui.ask_for_multiple_files(
    start_at=None, extensions=None, caption="Open Files"
) -> list[str] | None

Opens a file-picker that allows selecting one or more existing files. Returns a list of paths, or None on cancel.

paths = emzed_gui.ask_for_multiple_files(extensions=["csv"])
if paths is not None:
    tables = [emzed.io.load_csv(p) for p in paths]

ask_for_save¶

emzed_gui.ask_for_save(
    start_at=None, extensions=None, caption="Save As"
) -> str | None

Opens a save dialog. The file does not need to exist yet. If extensions is given, the dialog loops until the user enters a filename whose extension is in the list (or cancels).

path = emzed_gui.ask_for_save(
    start_at="/data/results",
    extensions=["csv"],
    caption="Save Table",
)
if path is not None:
    table.store(path)