Question

我正在分析开放食品事实数据集。数据集非常混乱，并且有一个名为“ quantity”的列，其中的条目如下：

'100 g'，
'142克（5盎司）'，
'12盎司'，
'200克'，
'340克（12盎司）'，
'10盎司（296毫升）'，
750毫升，
'1 l'，
250毫升 '8 OZ'，
750克（10.5盎司），
'1加仑（3.78 L）'，
'27盎司（1磅11盎司）765克'，
'75 cl'，

如您所见，值和度量单位到处都是！有时，数量是通过两种不同的度量给出的... 我的目标是在熊猫数据框中创建一个新列“ quantity_in_g”，在该列中，我从字符串中提取信息，并基于“ quantity”列中的克数创建一个整数Value。因此，如果“数量”列的值为“ 200 g”，我希望整数为200，如果它说“ 1 kg”，则希望整数为1000。我还想将其他度量单位转换为克。对于“ 2盎司”，我想要整数56，对于1 L，我想要1000。
有人可以帮我转换此列吗？我真的很感激！
预先感谢

Answer 1

raw_data_lst = ['100 g ','5 oz (142 g)','12 oz','200 g ','12 oz (340 g)','10 f oz (296ml)','750 ml','1 l','250 ml', '8 OZ',] 
# 10 f oz (296ml)  don't know what f is
# if more there is more data like this then gram_conv_dict.keys() loop over this instead of directly ... doing what i have done below

in_grams_colm = []
gram_conv_dict ={
    'g':1,
    'oz': 28.3495,
    'kg':1000,
    'l': 1000 # assuming 1 litre of water --> grams
    }
# ml --> g is tricky as density varies

def convert2num(string_num):
    try:
        return int(string_num)
    except ValueError:
        return float(string_num)

def get_in_grams(unit):
    try:
        return gram_conv_dict[unit.lower()]
    except:
        print('don\'t know how much grams is present in 1',unit+'.')

    return 1


for data in raw_data_lst:
    i = 0
    quantity_str =''
    quantity_num = 0
    while i < len(data):
        if  47 < ord(data[i]) < 58 or data[i] == '.':
            quantity_str+= data[i]
        else:
            # data[i] = '' most abbrv has at most length = 2 therefore data[i+1:i+3] or u can just send the whole data[i+1:]
            # gram_conv_dict[data[i+1:i+3].strip()] directly check if key exist
            break

        i+=1

    quantity_num = convert2num(quantity_str)*get_in_grams(data[i+1:i+3].strip()) # assuming each data has this format numberspace-- len 2 abbrv
    in_grams_colm.append(quantity_num) # if u want only integer int(quantity_num)

#print(in_grams_colm)

def nice_print():
    for _ in in_grams_colm:
        print('{:.2f}'.format(_))

nice_print()
'''
output

don't know how much grams is present in 1 f.
don't know how much grams is present in 1 ml.
don't know how much grams is present in 1 ml.
100.00
141.75
340.19
200.00
340.19
10.00
750.00
1000.00
250.00
226.80'''

从字符串中提取定量信息

1 个答案: