Examine the code below and give me a shorter way to do this.

def complement_char(c):
    # Write your code here
    if c=='A':
        return 'T'
    elif c== 'T':
        return 'A'
    elif c== 'C':
        return 'G'
    elif c== 'G':
        return 'C'
    else:
        return ' '