Python：无法读取文件

Question

我无法通过Python 2.7读取文件。我提示用户加载文件，一旦给出文件名，程序就会加载并打印文件中的行。

filename = raw_input("Filename to load: ")
print load_records(students, filename)

def load_records(students, filename):
    #loads student records from a file
    records = []
    in_file = open(filename, "r")
    for line in in_file:
        print line

但是，即使指定了整个文件路径，程序也会抛出'ValueError：混合迭代，读取方法会丢失数据。'