Python中如何使用变量创建文件名

file_name = 'example'print(f'{file_name}.txt')  # ????️ example.txtwith open(f'{file_name}.txt', 'w', encoding='utf-8') as f:    f.write('first line' + '
')    f.write('second line' + '
')

var1 = 'fql'var2 = 'jiyik'result = f'{var1}{var2}.csv'print(result)  # ????️ fqljiyik.csv

file_name = 'example'integer = 1234print(f'{file_name}_{integer}.txt')  # ????️ example_1234.txtwith open(f'{file_name}_{integer}.txt', 'w', encoding='utf-8') as f:    f.write('first line' + '
')    f.write('second line' + '
')

import timetimestamp = int(time.time())file_name = 'example'print(f'{file_name}_{timestamp}.txt')  # ????️ example_1665817197.txtwith open(f'{file_name}_{timestamp}.txt', 'w', encoding='utf-8') as f:    f.write('first line' + '
')    f.write('second line' + '
')

import csvfile_name = 'example'with open(file_name + '.csv', 'w', newline='', encoding='utf-8') as csvfile:    csv_writer = csv.writer(csvfile, delimiter=',',                            quoting=csv.QUOTE_MINIMAL)    csv_writer.writerow(['www', 'jiyik', 'Com'])

print('ab' + 'cd') # ????️ abcd

file_name = 123456result = str(file_name) + '.csv'print(result) # ????️ 123456.csv

file_name = 'example'print('{}.txt'.format(file_name))  # ????️ example.txtwith open('{}.txt'.format(file_name), 'w', encoding='utf-8') as f:    f.write('first line' + '
')    f.write('second line' + '
')

first = 'fql'last = 'jiyik'result = "{}_{}.txt".format(first, last)print(result)  # ????️ "fql_jiyik.txt"

first = 'fql'last = 'jiyik'result = "{f}_{l}.txt".format(f=first, l=last)print(result)  # ????️ "fql_jiyik.txt"

import timefirst = 'jiyik'result = "{}_{}.txt".format(first, int(time.time()))print(result)  # ????️ "jiyik_1665817957.txt"