python 實例

進度條

import sys, time


class ShowProcess(object):
    """
    顯示處理進度的類
    調用該類相關函數便可實現處理進度的顯示
    """
    # i = 0 # 當前的處理進度
    # max_steps = 0 # 總共須要處理的次數
    # max_arrow = 50 #進度條的長度

    # 初始化函數，須要知道總共的處理次數
    def __init__(self, max_steps):
        self.max_steps = max_steps    # 總共須要處理的次數
        self.max_arrow = 50    # 進度條的長度
        self.i = 0    # 當前的處理進度

    # 顯示函數，根據當前的處理進度i顯示進度
    # 效果爲[>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>]100.00%
    def show_process(self, i=None):
        if i is not None:
            self.i = i
        num_arrow = int(self.i * self.max_arrow / self.max_steps) # 計算顯示多少個'>'
        num_line = self.max_arrow - num_arrow # 計算顯示多少個'-'
        print(num_arrow,">")
        print(num_line,"-")
        percent = self.i * 100.0 / self.max_steps # 計算完成進度，格式爲xx.xx%
        print(percent,'百分比')
        process_bar = '\r' + '[' + '>' * num_arrow + '-' * num_line +']' + '%.2f' % percent + '%' #帶輸出的字符串，'\r'表示不換行回到最左邊
        sys.stdout.write(process_bar) # 這兩句打印字符到終端
        sys.stdout.flush()
        self.i += 1

    def close(self, words='done'):
        print('')
        print(words)
        self.i = 1


if __name__ == '__main__':
    max_steps = 1000

    process_bar = ShowProcess(max_steps)

    for i in range(max_steps + 1):
        process_bar.show_process()
        time.sleep(0.05)
    process_bar.close()