Python elif before_name not in self.friend_li:
时间: 2024-02-22 19:56:38 浏览: 22
这是一个条件语句,判断变量 `before_name` 是否不在 `self.friend_li` 列表中。如果 `before_name` 不在列表中,执行 `if` 语句后面的代码块;如果 `before_name` 在列表中,则继续判断下一条 `elif` 语句,如果所有的 `elif` 语句都不成立,则执行 `else` 语句后面的代码块。例如,可以这样使用该语句:
```
if before_name not in self.friend_li:
print("before_name 不在 friend_li 列表中")
elif before_name == "Alice":
print("before_name 是 Alice")
elif before_name == "Bob":
print("before_name 是 Bob")
else:
print("before_name 不是 Alice 也不是 Bob")
```
需要注意的是,在这个语句中,`self.friend_li` 是一个列表变量,`before_name` 是一个字符串变量,`not in` 是 Python 中的关键字,表示不在某个容器中。
相关问题
import os from PyQt5.QtCore import Qt from PyQt5.QtGui import QPixmap, QIcon from PyQt5.QtWidgets import QApplication, QWidget, QLabel, QVBoxLayout, QHBoxLayout, QTreeView, QFileSystemModel class ImageViewer(QWidget): def init(self, folder_path): super().init() self.folder_path = folder_path self.image_dict = {} self.current_image = None self.setWindowTitle("Image Viewer") self.setFixedSize(1000, 600) self.image_label = QLabel(self) self.image_label.setAlignment(Qt.AlignCenter) self.tree_view = QTreeView() self.tree_view.setMinimumWidth(250) self.tree_view.setMaximumWidth(250) self.model = QFileSystemModel() self.model.setRootPath(folder_path) self.tree_view.setModel(self.model) self.tree_view.setRootIndex(self.model.index(folder_path)) self.tree_view.setHeaderHidden(True) self.tree_view.setColumnHidden(1, True) self.tree_view.setColumnHidden(2, True) self.tree_view.setColumnHidden(3, True) self.tree_view.doubleClicked.connect(self.tree_item_double_clicked) self.main_layout = QHBoxLayout(self) self.main_layout.addWidget(self.tree_view) self.main_layout.addWidget(self.image_label) self.load_images() self.update_image() def load_images(self): for file_name in os.listdir(self.folder_path): if file_name.lower().endswith((".jpg", ".jpeg", ".png", ".gif", ".bmp")): file_path = os.path.join(self.folder_path, file_name) self.image_dict[file_name] = file_path current_image = list(self.image_dict.keys())[0] def update_image(self): if self.current_image is not None: pixmap = QPixmap(self.image_dict[self.current_image]) self.image_label.setPixmap(pixmap.scaled(self.width() - self.tree_view.width(), self.height(), Qt.KeepAspectRatio, Qt.SmoothTransformation)) def tree_item_double_clicked(self, index): file_name = self.model.fileName(index) if file_name in self.image_dict: self.current_image = file_name self.update_image() def keyPressEvent(self, event): if event.key() == Qt.Key_A: self.previous_image() elif event.key() == Qt.Key_D: self.next_image() elif event.key() in [Qt.Key_1, Qt.Key_2, Qt.Key_3, Qt.Key_4, Qt.Key_5]: self.save_text_file(event.key() - Qt.Key_0) def previous_image(self): if self.current_image is not None: file_names = list(self.image_dict.keys()) current_index = file_names.index(self.current_image) if current_index > 0: self.current_image = file_names[current_index - 1] else: self.current_image = file_names[-1] self.update_image() def next_image(self): if self.current_image is not None: file_names = list(self.image_dict.keys()) current_index = file_names.index(self.current_image) if current_index < len(file_names) - 1: self.current_image = file_names[current_index + 1] else: self.current_image = file_names[0] self.update_image() def save_text_file(self, number): if self.current_image is not None: file_name = self.current_image txt_file_path = os.path.join(self.folder_path, os.path.splitext(file_name)[0] + ".txt") with open(txt_file_path, "w") as file: file.write(str(number)) if name == "main": import sys app = QApplication(sys.argv) viewer = ImageViewer("D:/图片/wallpaper") viewer.show() sys.exit(app.exec_())这份代码实现不了使用键盘的A键向上翻页以及D键向下翻页,也实现不了键盘数字键生成相应txt文档,帮我分析一下错在哪里
这份代码在实现键盘事件的时候,使用了错误的函数名称。应该使用`keyPressEvent`而不是`key_press_event`函数。另外,在`save_text_file`函数中,应该先判断当前图片是否为`None`,再执行后续的代码。以下是修改后的代码:
```
import os
from PyQt5.QtCore import Qt
from PyQt5.QtGui import QPixmap, QIcon
from PyQt5.QtWidgets import QApplication, QWidget, QLabel, QVBoxLayout, QHBoxLayout, QTreeView, QFileSystemModel
class ImageViewer(QWidget):
def __init__(self, folder_path):
super().__init__()
self.folder_path = folder_path
self.image_dict = {}
self.current_image = None
self.setWindowTitle("Image Viewer")
self.setFixedSize(1000, 600)
self.image_label = QLabel(self)
self.image_label.setAlignment(Qt.AlignCenter)
self.tree_view = QTreeView()
self.tree_view.setMinimumWidth(250)
self.tree_view.setMaximumWidth(250)
self.model = QFileSystemModel()
self.model.setRootPath(folder_path)
self.tree_view.setModel(self.model)
self.tree_view.setRootIndex(self.model.index(folder_path))
self.tree_view.setHeaderHidden(True)
self.tree_view.setColumnHidden(1, True)
self.tree_view.setColumnHidden(2, True)
self.tree_view.setColumnHidden(3, True)
self.tree_view.doubleClicked.connect(self.tree_item_double_clicked)
self.main_layout = QHBoxLayout(self)
self.main_layout.addWidget(self.tree_view)
self.main_layout.addWidget(self.image_label)
self.load_images()
self.update_image()
def load_images(self):
for file_name in os.listdir(self.folder_path):
if file_name.lower().endswith((".jpg", ".jpeg", ".png", ".gif", ".bmp")):
file_path = os.path.join(self.folder_path, file_name)
self.image_dict[file_name] = file_path
self.current_image = list(self.image_dict.keys())[0]
def update_image(self):
if self.current_image is not None:
pixmap = QPixmap(self.image_dict[self.current_image])
self.image_label.setPixmap(pixmap.scaled(self.width() - self.tree_view.width(), self.height(), Qt.KeepAspectRatio, Qt.SmoothTransformation))
def tree_item_double_clicked(self, index):
file_name = self.model.fileName(index)
if file_name in self.image_dict:
self.current_image = file_name
self.update_image()
def keyPressEvent(self, event):
if event.key() == Qt.Key_A:
self.previous_image()
elif event.key() == Qt.Key_D:
self.next_image()
elif event.key() in [Qt.Key_1, Qt.Key_2, Qt.Key_3, Qt.Key_4, Qt.Key_5]:
self.save_text_file(event.key() - Qt.Key_0)
def previous_image(self):
if self.current_image is not None:
file_names = list(self.image_dict.keys())
current_index = file_names.index(self.current_image)
if current_index > 0:
self.current_image = file_names[current_index - 1]
else:
self.current_image = file_names[-1]
self.update_image()
def next_image(self):
if self.current_image is not None:
file_names = list(self.image_dict.keys())
current_index = file_names.index(self.current_image)
if current_index < len(file_names) - 1:
self.current_image = file_names[current_index + 1]
else:
self.current_image = file_names[0]
self.update_image()
def save_text_file(self, number):
if self.current_image is not None:
file_name = self.current_image
txt_file_path = os.path.join(self.folder_path, os.path.splitext(file_name)[0] + ".txt")
with open(txt_file_path, "w") as file:
file.write(str(number))
if __name__ == "__main__":
import sys
app = QApplication(sys.argv)
viewer = ImageViewer("D:/图片/wallpaper")
viewer.show()
sys.exit(app.exec_())
```
解释下面代码: def __init__(self, filename, sheet_name=None, sheet_index=None): self.workbook = xlrd.open_workbook(filename) # 文件对象 if not sheet_name and not sheet_index: self.sheet = self.workbook.sheet_by_index(0) elif sheet_name: self.sheet = self.workbook.sheet_by_name(sheet_name) elif sheet_index: self.sheet = self.workbook.sheet_by_index(sheet_index) self.current_row = 2 # 表示当前行号 self.keys = [] # 初始化keys 对象
这段代码定义了一个类,初始化方法包含三个参数:文件名、工作表名称和工作表索引。首先,使用xlrd库打开文件对象,然后根据给定的sheet_name或sheet_index选择工作表。如果没有给定,则默认选择第一个工作表。然后,初始化当前行号为2(因为通常第一行是标题),并将keys列表初始化为空。这个类的主要作用是读取Excel文件中的数据,并对数据进行处理。