的Python在DOT格式读取文件，并返回城市名单

Question

大家好，问题是这样的，这是家庭作业的问题，说实话，但我只是坚持其一直到永远。 我的问题是，因为城市在每个行中，我们如何通过线迭代线和城市名称返回到一个列表不同的索引位置？（可以让我开始任何帮助将不胜感激我不是懒惰我真的为几个小时就这项工作）

citylist(filename) reads a file in the DOT format 
     and returns a list of city names, one for each line in 
     the file. The DOT format may have trailing spaces on 
     the city name; make sure citylist creates a list of 
     city names with trailing spaces removed (easy using 
     Python's strip() method). Two test cases are shown 
     below, for lines at index 3 and 347. 

citylist("DOT500.txt")[3] 
    'TUCSON' 

citylist("DOT500.txt")[347] 
    'NORTH VILLE' 

及以下的DOT文件（的一部分）

1 958164 TOYOTA MOTOR CORPORATION TOYOTA LAND CRUISER 1994  19941223 N 0 0 SERVICE BRAKES, HYDRAULIC:ANTILOCK ARNOLD   CA JT3DJ81W8R0 19950103 19950103   ABS SYSTEM FAILURE, AT 20MPH. TT EVOQ                         V 

2 958156 TOYOTA MOTOR CORPORATION TOYOTA PASEO 1994 Y 19941226 N 0 0 PARKING BRAKE:CONVENTIONAL SAN JOSE  CA JT2EL45U5R0 19950103 19950103  1 PARKED ON FLAT SURFACE EMERGENCY BRAKING ENGAGED VEHICLE ROLLED REARWARD. TT EVOQ                         V 

3 958124 TOYOTA MOTOR CORPORATION TOYOTA COROLLA 1994 Y 19941128 N 0 0 AIR BAGS:FRONTAL PHOENIX   AZ  19950103 19950103   UPON FRONTAL COLLISION, AIR BAG FAILED TO DEPLOY. VEHICLE CLASSIFIED AS TOTALED. PLEASE DESCRIBE DETAILS. TT EVOQ                         V 

4 958122 NISSAN NORTH AMERICA, INC. NISSAN MAXIMA 1994  19950103 N 0 0 SUSPENSION TUCSON   AZ JN1HJ01F4RT 19950103 19950103   THE STRUT WAS BAD THERE IS A NOISE ON THE PASSENGER SIDE DOOR AND THE ENGINE LIGHT MALFUNCTION. TT EVOQ                         V 

5 958122 NISSAN NORTH AMERICA, INC. NISSAN MAXIMA 1994  19950103 N 0 0 ENGINE AND ENGINE COOLING:ENGINE TUCSON   AZ JN1HJ01F4RT 19950103 19950103   THE STRUT WAS BAD THERE IS A NOISE ON THE PASSENGER SIDE DOOR AND THE ENGINE LIGHT MALFUNCTION. TT EVOQ                         V 

6 958247 NISSAN NORTH AMERICA, INC. NISSAN PATHFINDER 1994   N 0 0 SUSPENSION:FRONT ABINGDON  MD  19950103 19950103   FRONT TIRES SHOW EXCESSIVE WEAR AND STEEL BELTS. NISSAN IS OFFERING TO REPLACE TWO TIRES. TT EVOQ                         V 

7 958143 FORD MOTOR COMPANY FORD MUSTANG 1991  19941119 Y 0 0 SEATS:FRONT ASSEMBLY:POWER ADJUST PENSICOLA  FL  19950103 19950103   DRIVER SIDE POWER SEAT CAUGHT FIRE. TT EVOQ                         V 

8 958141 DAIMLERCHRYSLER CORPORATION CHRYSLER NEW YORKER 1989  19950103 N 0 0 POWER TRAIN:AUTOMATIC TRANSMISSION LEVITTOWN  NY 1C3BC4639KD 19950103 19950103  2 TRANSMISSION NOT SHIFTING OUT OF 2ND GEAR, WENT INTO LIM MODE/TRANSMMION NOT SHIFTING THEN JUMPED OUT OF GEAR. *AK EVOQ                         V 

9 958128 DAIMLERCHRYSLER CORPORATION DODGE SHADOW 1990 Y 19941224 N 0 0 SERVICE BRAKES, HYDRAULIC:ANTILOCK WILMINGTON  DE 1B3XT44KXLN 19950103 19950103  1 ABS: EXPERIENCED ANTI-LOCK BRAKE FAILURE/EXTENDED STOPPING DISTANCE, RESULTING IN AN ACCIDENT, IMPACT 12:00 POSITION SPEED, 20 MPH. TT EVOQ                         V 

10 958128 DAIMLERCHRYSLER CORPORATION DODGE SHADOW 1990 Y 19940412 N 0 0 SUSPENSION:FRONT WILMINGTON  DE 1B3XT44KXLN 19950103 19950103  1 MISALIGNMENT, CAUSING VEHICLE TO VEER TO THE CENTER. *AK EVOQ                         V 

11 958128 DAIMLERCHRYSLER CORPORATION DODGE SHADOW 1990 Y 19941117 N 0 0 ENGINE AND ENGINE COOLING:ENGINE WILMINGTON  DE 1B3XT44KXLN 19950103 19950103  1 ENGINE MOTOR MOUNTS FAILED, RESULTING IN ENGINE NOISE. *AK EVOQ                         V 

12 958168 GENERAL MOTORS CORP. CHEVROLET SUBURBAN 1995 Y 19950101 N 0 0 POWER TRAIN:AUTOMATIC TRANSMISSION:GEAR POSITION INDICATION (PRNDL) SHAFTFBURG  MI  19950103 19950103   VEHICLE ROLLED DOWN HILL WHILE IN PARK, AND INTO A TREE. TT EVOQ                         V 

13 958169 GENERAL MOTORS CORP. GEO METRO 1995 Y 19941225 N 1 0 SERVICE BRAKES, HYDRAULIC:FOUNDATION COMPONENTS NORFOLK   VA  19950103 19950103   BRAKES WOULD NOT WORK ON SEVERAL OCCASIONS, LAST INSTANCE RESULTED IN AN ACCIDENT. TT EVOQ  

Answer 1

在一般情况下，这将是真的，真的很难。但是我们可以看到他们是否让我们更容易。我们可以在一条线上阅读，看看它：

In [31]: first_line = open("toyota.dot").readline() 

In [32]: print repr(first_line) 
' 1\t958164\tTOYOTA MOTOR CORPORATION\tTOYOTA\tLAND CRUISER\t1994\t\t19941223\tN\t0\t0\tSERVICE BRAKES, HYDRAULIC:ANTILOCK\tARNOLD  \tCA\tJT3DJ81W8R0\t19950103\t19950103\t\t\tABS SYSTEM FAILURE, AT 20MPH. TT\tEVOQ\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tV\t\n' 

查看所有这些\t符号？我们很幸运 - 各栏由标签分隔！因此，一个方法是使用在线路.split()方法将它们分解成列：

In [33]: first_line.split("\t") 
Out[33]: 
[' 1', 
'958164', 
'TOYOTA MOTOR CORPORATION', 
'TOYOTA', 
'LAND CRUISER', 
'1994', 
[... etc ...] 
'\n'] 

，然后我们可以提取列：

In [34]: first_line.split("\t")[11] 
Out[34]: 'SERVICE BRAKES, HYDRAULIC:ANTILOCK' 

In [35]: first_line.split("\t")[12] 
Out[35]: 'ARNOLD  ' 

，摆脱了空间。

In [36]: first_line.split("\t")[12].strip() 
Out[36]: 'ARNOLD' 

可以使用

with open("toyota.dot") as data: 
    for line in data: 
     parts = line.split("\t") 

模式来遍历行，剩下的你应该能够拼凑。

旁白：其实我使用csv.reader与delimiter="\t"，但是这可能有点出乎老师是什么了。]