如何使用python打印新行中函数返回的输出？

Question

I have 243607 ips in the log file. the output of a function is displaying unique ips continuously so that i can't able to check whether the output ips are unique. So i want each ip to be print in seprate line. as i'm new to python i can't able to figure it out. is there any way to do it?

I also want the count of the ips printed

def unique_ips(): 
    f = open('epiclogs.txt','r')
    ips = set(line.split()[0] 
    for line in f:
        if not line.isspace()) 
            ip = line.split()[0] 
            ips.add(ip) 

    return ips

if name__=='__main':
    print unique_ips() 

Answer 1

The requirements are not complete:

1. The format of the log file is unknown.
2. The format of the output file (eg sorted?)

My assumptions

1. The IP addresses are located in the first column
2. The output format should be '[count] [ip address]'

Test data

10.1.10.190 http://example.com/t1 404
10.1.10.171 http://example.com/t1 404

10.1.10.180 http://example.com/t2 200
10.1.10.190 http://example.com/t1 404
10.1.11.180 http://example.com/t3 302

Program

#!/usr/bin/env python
# 
# Counts the IP addresses of a log file.
# 
# Assumption: the IP address is logged in the first column.
# Example line: 10.1.10.190 http://example.com/t1 404
#

import sys

def extract_ip(line):
    '''Extracts the IP address from the line.
       Currently it is assumed, that the IP address is logged in
       the first column and the columns are space separated.'''
    return line.split()[0]

def increase_count(ip_dict, ip_addr):
    '''Increases the count of the IP address.
       If an IP address is not in the given dictionary,
       it is initially created and the count is set to 1.'''
    if ip_addr in ip_dict:
        ip_dict[ip_addr] += 1
    else:
        ip_dict[ip_addr] = 1

def read_ips(infilename):
    '''Read the IP addresses from the file and store (count)
       them in a dictionary - returns the dictionary.'''
    res_dict = {}
    log_file = file(infilename)
    for line in log_file:
        if line.isspace():
            continue
        ip_addr = extract_ip(line)
        increase_count(res_dict, ip_addr)
    return res_dict

def write_ips(outfilename, ip_dict):
    '''Write out the count and the IP addresses.'''
    out_file = file(outfilename, "w")
    for ip_addr, count in ip_dict.iteritems():
        out_file.write("%5d\t%s\n" % (count, ip_addr))
    out_file.close()

def parse_cmd_line_args():
    '''Return the in and out file name.
       If there are more or less than two parameters,
       an error is logged in the program is exited.'''
    if len(sys.argv)!=3:
        print("Usage: %s [infilename] [outfilename]" % sys.argv[0])
        sys.exit(1)
    return sys.argv[1], sys.argv[2]

def main():
    infilename, outfilename = parse_cmd_line_args()
    ip_dict = read_ips(infilename)
    write_ips(outfilename, ip_dict)

if __name__ == "__main__":
    main()

Comment

I like small functions - each of them does exactly one thing. IMHO this makes the program easier to understand.

Answer 2

Havn't checked your code works or not, but added new lines to it, which can achieve your task.

try this,

def unique_ips(): 
    f = open('epiclogs.txt','r')
    fout = open('uniqueip.txt','w') # Added
    ips = set(line.split()[0] 
    for line in f:
        if not line.isspace()): 
            ip = line.split()[0] 
            ips.add(ip) 
            fout.write("%s\n"%ip) # Added
    f.close() # Added
    fout.flush() # Added
    fout.close() # Added
    return ips

if name__=='__main':
    print unique_ips() 

Answer 3

unique_ips() returns a set , which means each IP address only appears once. If you want to see the addresses line by line in a file, you can change the print unique_ips() line to:

if __name__== '__main__':
    f = file('ip_addresses', 'w')
    for ip in unique_ips():
        f.write(ip + '\n')