python读取csv文件

import csv 
csvfile = open('E:/tests/2022-01/data-text.csv', 'rb') #rb 以只读和二进制的方式打开文件
reader = csv.reader(csvfile) 

for row in reader:
    print (row)

报错 Error: iterator should return strings, not bytes (did you open the file in text mode?)

解决办法:将文件打开类型设置为rt或者r

import csv 
csvfile = open('E:/tests/2022-01/data-text.csv', 'r') 
reader = csv.reader(csvfile) 

for row in reader:
    print (row)

读取数据记录展示为字典形式

import csv 
csvfile = open('E:/tests/2022-01/data-text.csv', 'r') 
reader = csv.DictReader(csvfile) 

for row in reader:
    print (row)

python解析excel文件

处理excel文件的主要库：xlrd（读取）、xlwt（写入）、xlutils（高级操作）

1.查看工作表中的sheet名

import xlrd 
book = xlrd.open_workbook(file_path)
for sheet in book.sheets():
    print (sheet.name)

2.查看工作表指定sheet的内容

import xlrd
book = xlrd.open_workbook(file_path) 
sheet = book.sheet_by_name('sheet1') 
print (sheet)

print(sheet.nrows) #返回sheet表中的记录数

#遍历行数，返回每一行的内容（扩展：返回任意行的数据）
for i in range(sheet.nrows):
    print (sheet.row_values(i))

#遍历行数，返回指定范围的数据（执行结果返回第14-19行数据）
count = 0
for i in range(sheet.nrows):
    if count < 20:
        if i >= 14:
            row = sheet.row_values(i) 
            print (i, row )
    count += 1

其中：

3.查看sheet中每个元素

#嵌套for循环，将每行元素以单个形式展示
for i in range(sheet.nrows):
    print (sheet.row_values(i))
    for cell in row:
        print (cell)

4.将提取信息以字典形式展示

• 设置country作为data字段的键

import xlrd 
book = xlrd.open_workbook('E:/tests/2022-01/SOWC 2014 Stat Tables_Table 9.xlsx')
sheet = book.sheet_by_name('Table 9 ') 
#print (sheet)

count = 0 
data = {}
for i in range(sheet.nrows):
    if count < 10:
        if i >= 14:
            row = sheet.row_values(i)
            country = row[1]
            data[country] = {}  #将国家设为data的键，对应的值设为另一个字典
            count += 1 
print(data)

#本次执行结果展示行数为14-23行数据，i<14时count+=1不执行，此时count=0

• 设置country键对应值（以字典形式存储）

import xlrd 
book = xlrd.open_workbook('E:/tests/2022-01/SOWC 2014 Stat Tables_Table 9.xlsx')
sheet = book.sheet_by_name('Table 9 ') 

data = {}
for i in range(14, sheet.nrows):
    row = sheet.row_values(i)
    country = row[1]
    data[country] = {'child_labor': {'total': [],'male': [],'female': []},
                     'child_marriage': {'married_by_15': [],'married_by_18': []}
                     }
print (data['Afghanistan'])


#data[country]具体数据用索引获得
data[country] = {'child_labor': {'total': [row[4], row[5]],'male': [row[6], row[7]],'female': [row[8], row[9]]},
                 'child_marriage': {'married_by_15': [row[10], row[11]],'married_by_18': [row[12], row[13]]}
                 }



#pprint按输出数据的结构展示
import pprint
pprint.pprint(data)

• 上述代码整理

import xlrd 
book = xlrd.open_workbook('E:/tests/2022-01/SOWC 2014 Stat Tables_Table 9.xlsx')
sheet = book.sheet_by_name('Table 9 ') 

data = {}
for i in range(14, sheet.nrows):
    row = sheet.row_values(i)
    country = row[1]
    data[country] = {'child_labor': {'total': [row[4], row[5]],'male': [row[6], row[7]],'female': [row[8], row[9]]},
                 'child_marriage': {'married_by_15': [row[10], row[11]],'married_by_18': [row[12], row[13]]}
                 }
    if country == 'Zimbabwe':
        break

import pprint
pprint.pprint(data) 

python 判断excel文件是否存在

Filepath = 'E:/文件路径/'
for i in range(1,8):
    Filename = Filepath + '%d'%(i)+'.xlsx' #excel文件名
    if os.path.exists(Filename) == False:
        writer = pd.ExcelWriter(Filename)
writer.save()
writer.close()