我有一个csv文件
1 , name , 1012B-Amazon , 2044C-Flipcart , Bosh27-Walmart
2 , name , Kelvi20-Flipcart, LG-Walmart
3, name , Kenstar-Walmart, Sony-Amazon , Kenstar-Flipcart
4, name , LG18-Walmart, Bravia-Amazon
我需要由网站重新排列行，即-之后的部分；
1, name , 1012B-Amazon , 2044C-Flipcart , Bosh27-Walmart
2, name , , Kelv20-Flipcart, LG-Walmart
3, name , Sony-Amazon, Kenstar-Flipcart ,Kenstar-Walmart
4, name , Bravia-Amazon, ,LG18-Walmart
可以使用熊猫吗？找到字符串的存在并重新排列，然后遍历所有行，并在下一个字符串中重复此操作？我浏览了Series.str.contains和str.extract的文档，但是找不到解决方案。
答案 0 :(得分：1)
将sorted与key一起使用
df.iloc[:,1:].apply(lambda x : sorted(x,key=lambda y: (y=='',y)),1)
2 3 4 5
1 ABC DEF GHI JKL
2 ABC DEF GHI
3 ABC DEF GHI JKL
#df.iloc[:,1:]=df.iloc[:,1:].apply(lambda x : sorted(x,key=lambda y: (y=='',y)),1)
自从您提到reindex以来，我认为get_dummies会起作用
s=pd.get_dummies(df.iloc[:,1:],prefix ='',prefix_sep='')
s=s.drop('',1)
df.iloc[:,1:]=s.mul(s.columns).values
df
1 2 3 4 5
1 name ABC DEF GHI JKL
2 name ABC DEF GHI
3 name ABC DEF GHI JKL
答案 1 :(得分：1)
假定空值为np.nan：
# Fill in the empty values with some string to allow sorting
df.fillna('NaN', inplace=True)
# Flatten the dataframe, do the sorting and reshape back to a dataframe
pd.DataFrame(list(map(sorted, df.values)))
0 1 2 3
0 ABC DEF GHI JKL
1 ABC DEF GHI NaN
2 ABC DEF GHI JKL
更新
给出问题的更新和示例数据如下
df = pd.DataFrame({'name': ['name1', 'name2', 'name3', 'name4'],
'b': ['1012B-Amazon', 'Kelvi20-Flipcart', 'Kenstar-Walmart', 'LG18-Walmart'],
'c': ['2044C-Flipcart', 'LG-Walmart', 'Sony-Amazon', 'Bravia-Amazon'],
'd': ['Bosh27-Walmart', np.nan, 'Kenstar-Flipcart', np.nan]})
可能的解决方案是
def foo(df, retailer):
# Find cells that contain the name of the retailer
mask = df.where(df.apply(lambda x: x.str.contains(retailer)), '')
# Squash the resulting mask into a series
col = mask.max(skipna=True, axis=1)
# Optional: trim the name of the retailer
col = col.str.replace(f'-{retailer}', '')
return col
df_out = pd.DataFrame(df['name'])
for retailer in ['Amazon', 'Walmart', 'Flipcart']:
df_out[retailer] = foo(df, retailer)
导致
name Amazon Walmart Flipcart
0 name1 1012B Bosh27 2044C
1 name2 LG Kelvi20
2 name3 Sony Kenstar Kenstar
3 name4 Bravia LG18
答案 2 :(得分：1)
问题更新后编辑：
这是abc csv：
1,name,ABC,GHI,DEF,JKL
2,name,GHI,DEF,ABC,
3,name,JKL,GHI,ABC,DEF
这是公司csv（必须仔细看逗号）：
1,name,1012B-Amazon,2044C-Flipcart,Bosh27-Walmart
2,name,Kelvi20-Flipcart,LG-Walmart,
3,name,Kenstar-Walmart,Sony-Amazon,Kenstar-Flipcart
4,name,LG18-Walmart,Bravia-Amazon,
这是代码
import pandas as pd
import numpy as np
#These solution assume that each value that is not empty is not repeated
#within each row. If that is not the case for your data, it would be possible
#to do some transformations that the non empty values are unique for each row.
#"get_company" returns the company if the value is non-empty and an
#empty value if the value was empty to begin with:
def get_company(company_item):
if pd.isnull(company_item):
return np.nan
else:
company=company_item.split('-')[-1]
return company
#Using the "define_sort_order" function, one can retrieve a template to later
#sort all rows in the sort_abc_rows function. The template is derived from all
#values, aside from empty values, within the matrix when "by_largest_row" = False.
#One could also choose the single largest row to serve as the
#template for all other rows to follow. Both options work similarly when
#all rows are subsets of the largest row i.e. Every element in every
#other row (subset) can be found in the largest row (or set)
#The difference relates to, when the items contain unique elements,
#Whether one wants to create a table with all sorted elements serving
#as the columns, or whether one wants to simply exclude elements
#that are not in the largest row when at least one non-subset row does not exist
#Rather than only having the application of returning the original data rows,
#one can get back a novel template with different values from that of the
#original dataset if one uses a function to operate on the template
def define_sort_order(data,by_largest_row = False,value_filtering_function = None):
if not by_largest_row:
if value_filtering_function:
data = data.applymap(value_filtering_function)
#data.values returns a numpy array
#with rows and columns. .flatten()
#puts all elements in a 1 dim array
#set gets all unique values in the array
filtered_values = list(set((data.values.flatten())))
filtered_values = [data_value for data_value in filtered_values if not_empty(data_value)]
#sorted returns a list, even with np.arrays as inputs
model_row = sorted(filtered_values)
else:
if value_filtering_function:
data = data.applymap(value_filtering_function)
row_lengths = data.apply(lambda data_row: data_row.notnull().sum(),axis = 1)
#locates the numerical index for the row with the most non-empty elements:
model_row_idx = row_lengths.idxmax()
#sort and filter the row with the most values:
filtered_values = list(set(data.iloc[model_row_idx]))
model_row = [data_value for data_value in sorted(filtered_values) if not_empty(data_value)]
return model_row
#"not_empty" is used in the above function in order to filter list models that
#they no empty elements remain
def not_empty(value):
return pd.notnull(value) and value not in ['',' ',None]
#Sorts all element in each _row within their corresponding position within the model row.
#elements in the model row that are missing from the current data_row are replaced with np.nan
def reorder_data_rows(data_row,model_row,check_by_function=None):
#Here, we just apply the same function that we used to find the sorting order that
#we computed when we originally #when we were actually finding the ordering of the model_row.
#We actually transform the values of the data row temporarily to determine whether the
#transformed value is in the model row. If so, we determine where, and order #the function
#below in such a way.
if check_by_function:
sorted_data_row = [np.nan]*len(model_row) #creating an empty vector that is the
#same length as the template, or model_row
data_row = [value for value in data_row.values if not_empty(value)]
for value in data_row:
value_lookup = check_by_function(value)
if value_lookup in model_row:
idx = model_row.index(value_lookup)
#placing company items in their respective row positions as indicated by
#the model_row #
sorted_data_row[idx] = value
else:
sorted_data_row = [value if value in data_row.values else np.nan for value in model_row]
return pd.Series(sorted_data_row)
##################### ABC ######################
#Reading the data:
#the file will automatically include the header as the first row if this the
#header = None option is not included. Note: "name" and the 1,2,3 columns are not in the index.
abc = pd.read_csv("abc.csv",header = None,index_col = None)
# Returns a sorted, non-empty list. IF you hard code the order you want,
# then you can simply put the hard coded order in the second input in model_row and avoid
# all functions aside from sort_abc_rows.
model_row = define_sort_order(abc.iloc[:,2:],False)
#applying the "define_sort_order" function we created earlier to each row before saving back into
#the original dataframe
#lambda allows us to create our own function without giving it a name.
#it is useful in this circumstance in order to use two inputs for sort_abc_rows
abc.iloc[:,2:] = abc.iloc[:,2:].apply(lambda abc_row: reorder_data_rows(abc_row,model_row),axis = 1).values
#Saving to a new csv that won't include the pandas created indices (0,1,2)
#or columns names (0,1,2,3,4):
abc.to_csv("sorted_abc.csv",header = False,index = False)
################################################
################## COMPANY #####################
company = pd.read_csv("company.csv",header=None,index_col=None)
model_row = define_sort_order(company.iloc[:,2:],by_largest_row = False,value_filtering_function=get_company)
#the only thing that changes here is that we tell the sort function what specific
#criteria to use to reorder each row by. We're using the result from the
#get_company function to do so. The custom function get_company, takes an input
#such as Kenstar-Walmart, and outputs Walmart (what's after the "-").
#we would then sort by the resulting list of companies.
#Because we used the define_sort_order function to retrieve companies rather than company items in order,
#We need to use the same function to reorder each element in the DataFrame
company.iloc[:,2:] = company.iloc[:,2:].apply(lambda companies_row: reorder_data_rows(companies_row,model_row,check_by_function=get_company),axis=1).values
company.to_csv("sorted_company.csv",header = False,index = False)
#################################################
这是sorted_abc.csv的第一个结果：
1 name ABC DEF GHI JKL
2 name ABC DEF GHI NaN
3 name ABC DEF GHI JKL
将代码修改为所查询的后续格式后， 这是由于运行 脚本。
1 name 1012B-Amazon 2044C-Flipcart Bosh27-Walmart
2 name NaN Kelvi20-Flipcart LG-Walmart
3 name Sony-Amazon Kenstar-Flipcart Kenstar-Walmart
4 name Bravia-Amazon NaN LG18-Walmart
希望对您有帮助！